On 3/12/2023 2:03 PM, Cursitor Doom wrote:
> On Sat, 11 Mar 2023 15:30:11 -0800 (PST), Animal <tabbypurr@gmail.com>
> wrote:
>
>> On Saturday, 11 March 2023 at 15:51:41 UTC, Rob Morley wrote:
>>> On Sat, 11 Mar 2023 10:26:47 -0000
>>> "Brian Gaff" <brian...@gmail.com> wrote:
>>>
>>>> So, what is the basic difference from the way it works. To me from my
>>>> old school days, when I could see, you are basically heating stuff up
>>>> and using the welding rod to basically brace it as you want it to be.
>>>>
>>> Indeed, basically hot glue for metal, but that's done in different
>>> ways. If we stick (no pun intended) to electric arc welding then you
>>> can supply the heating current through a regular transformer at mains
>>> frequency, or using semiconductors that rectify and switch the incoming
>>> AC mains in the same way as a switched-mode PSU; this uses a smaller
>>> transformer at higher frequency and efficiency, so it's typically
>>> lighter and more compact with better duty cycle than a traditional
>>> transformer machine. It also allows fine automatic control of the output
>>> current leading to a more stable arc, and may also support multi-mode
>>> processes so one machine can handle MIG, AC/DC TIG and stick welding.
>>> Also the increasing cost of copper and the decreasing cost of IGBT as
>>> the technology has matured favours inverter machines.
>>>
>>> TLDR:
>>> Inverter welder is more luggable, better arc control but a buzz box is
>>> likely to survive longer esp. in harsh conditions because it's so
>>> simple.
>>
>> Age & quality are also fairly big factors. An old Sip or Oxford should be reliable, a new invertor thing is to often chinesium junk.
>
> That is a major consideration, in fact. The complexity of some of
> these newer inverter welders renders them less reliable overall than
> the old traditional Oxfords and Olympic oil-cooled transformer types
> which just soldier on and on over decades without issue. My 320 amp
> oil-cooled jobbie will be 50 years old this year and still functions
> like the day it was made. Will we be able to say the same for even the
> best inverter types produced today? Nope!
>

Do the circuit analysis, and spot the weakness.

https://www.homemade-circuits.com/wp-content/uploads/2014/07/welding2Bpower2Bsupply.png

To me, the biggest weakness is "noise on rails". A large enough transient
on mains could damage the switching transistors, but then half the
stuff in your house would also be blown to hell and back if that
happened.

That circuit should have some filtering before the full wave bridge, to
stop switching noise from going back onto mains.

Where the design has an advantage, is the transformer does not
have to be as big, at the switching frequency used.

That circuit has three snubber networks, and it has series
resistors on the switching transistor gates to prevent "punchthru".
Transistors with 3000pF gate capacitance, a couple amperes
of current flows from the pre-drive, into the gate, and
this can burn a hole in the gate, if the peak current is too high.
The circuit has the necessary series resistors to reduce the peak current value.

The dot on one of the transformer windings , is the wrong way round :-)

There are some circuit functions, that are notorious for failure,
such as variable speed motor drive. But I don't know the reason
for that.

Paul

On 13/03/2023 23:33, Cursitor Doom wrote:
> On Sun, 12 Mar 2023 20:51:49 +0000, Chris Green <cl@isbd.net> wrote:
>
>> Cursitor Doom <cd@notformail.com> wrote:
>>> On Sat, 11 Mar 2023 15:30:11 -0800 (PST), Animal <tabbypurr@gmail.com>
>>> wrote:
>>>
>>>> On Saturday, 11 March 2023 at 15:51:41 UTC, Rob Morley wrote:
>>>>> On Sat, 11 Mar 2023 10:26:47 -0000
>>>>> "Brian Gaff" <brian...@gmail.com> wrote:
>>>>>
>>>>>> So, what is the basic difference from the way it works. To me from my
>>>>>> old school days, when I could see, you are basically heating stuff up
>>>>>> and using the welding rod to basically brace it as you want it to be.
>>>>>>
>>>>> Indeed, basically hot glue for metal, but that's done in different
>>>>> ways. If we stick (no pun intended) to electric arc welding then you
>>>>> can supply the heating current through a regular transformer at mains
>>>>> frequency, or using semiconductors that rectify and switch the incoming
>>>>> AC mains in the same way as a switched-mode PSU; this uses a smaller
>>>>> transformer at higher frequency and efficiency, so it's typically
>>>>> lighter and more compact with better duty cycle than a traditional
>>>>> transformer machine. It also allows fine automatic control of the output
>>>>> current leading to a more stable arc, and may also support multi-mode
>>>>> processes so one machine can handle MIG, AC/DC TIG and stick welding.
>>>>> Also the increasing cost of copper and the decreasing cost of IGBT as
>>>>> the technology has matured favours inverter machines.
>>>>>
>>>>> TLDR:
>>>>> Inverter welder is more luggable, better arc control but a buzz box is
>>>>> likely to survive longer esp. in harsh conditions because it's so
>>>>> simple.
>>>>
>>>> Age & quality are also fairly big factors. An old Sip or Oxford should
>>> be reliable, a new invertor thing is to often chinesium junk.
>>>
>>> That is a major consideration, in fact. The complexity of some of
>>> these newer inverter welders renders them less reliable overall than
>>> the old traditional Oxfords and Olympic oil-cooled transformer types
>>> which just soldier on and on over decades without issue. My 320 amp
>>> oil-cooled jobbie will be 50 years old this year and still functions
>>> like the day it was made. Will we be able to say the same for even the
>>> best inverter types produced today? Nope!
>>
>> Yesp! Modern, very complex, cars are *way* more reliable than those
>> of decades ago. Well designed electronics is amazingly reliable.
>
> They're "amazingly reliable" for the first few years, but I can tell
> you from very extensive first hand experience that vintage electronics
> age just the same as everything else. And the more complex they are,
> the harder it becomes to trace the fault and fix it - and that may
> become next to impossible when the manufacturer has used custom chips
> had short production runs.

You see it with a lot of 80 era microcomputers. The NMOS process used on
many results in failures with age, and there were many custom ICs and
application specific gate arrays used. So they are getting increasingly
hard to repair.

On the more well known names you are starting to see quite decent supply
of re-engineered chips using off the shelf EPLDs and FPGAs mounted on
DIL shaped PCBs as drop in replacements.

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

On 13/03/2023 23:33, Cursitor Doom wrote:
>> Yesp! Modern, very complex, cars are*way* more reliable than those
>> of decades ago. Well designed electronics is amazingly reliable.

> They're "amazingly reliable" for the first few years, but I can tell
> you from very extensive first hand experience that vintage electronics
> age just the same as everything else. And the more complex they are,
> the harder it becomes to trace the fault and fix it - and that may
> become next to impossible when the manufacturer has used custom chips
> had short production runs.

Vintage electronics are, by definition, not very complex.
Custom chips only appeared in the 90s really.

--
Future generations will wonder in bemused amazement that the early
twenty-first century’s developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen

On 14/03/2023 07:47, Paul wrote:
> On 3/13/2023 7:50 PM, Rod Speed wrote:
>> On Mon, 13 Mar 2023 21:04:20 +1100, Fredxx <fredxx@spam.uk> wrote:
>>
>>> Even electronics ICs are designed to last a number of years.
>>
>> BULLSHIT.
>
> If you read enough IBM documentation, this value is "100,000 hours".
>
> We did not use such a metric in our fab. The electromigration
> frequency was just "X", and there was no qualifying "for 100,000 hour
> life".
> Whatever our number was, it wasn't in print. Maybe our reference
> point was in some separate generic reliability document
> I never saw. IBM likes to put that reference figure in
> documentation.
>
> But this is a reference point, for technology choices.
> It basically says, the target most of the time, is
> 100,000 hours minimum, when there is a discussion about
> potential things affecting reliability (max frequency).
> It does not mean they go about ruining things on purpose
> to make the characteristic 100,000. It's just a point
> selected, so you can compare two things at the 100,000 point,
> for their performance.
>
> The customer designing integrated circuits in that fab,
> does not desire the chip to die precisely at 100,000 hours.
>
> If you run a CMOS chip at 135C, the dopant migration might
> make it last 100,000 hours, but the datasheet tells you to
> run it no higher than 100C die temp. And then Arrhenius
> (curve fit), tells you how many million hours it will last.
>
> A chip can last a lot longer than that.
>
> If loose chlorine pollution happens to be inside the
> molded plastic IC package, the IC might only last a year or two.
> IBM traced a case like this, to the usage of a marker
> pen to mark bad die during wafer-sort. (That's where
> you do an ICCC test while probing die sites before the
> wafer gets scribed.)
>
> It's even possible they don't do
> wafer sort any more, and just package it all, and
> that's where bags of 555 timers with a dead short
> between the legs, come from :-) If there was a wafer
> sort for quiescent current, it would have tossed those
> die. But the ICCC test was only really a great idea,
> when CMOS was 3u. At 65nm, there is enough leakage,
> the quiescent current is not a good enough indicator
> of chip quality. You might have to run test vectors
> instead. And packaged parts are likely easier to cool,
> for the high power ones. (Like the ones with a thermal
> slug on the bottom.)
>
> *******
>
> There is one processor, which is rated for 300C.
> But for only 1000 hours :-) This is a processor
> sent down boreholes, like for an oil exploratory hole.
> They characterize at that temperature, because a
> major customer asked them to. There is no industry
> standard for 300C integrated circuits. Mil spec
> is the most stringent "widely seen" point. I would
> think your little printed circuit board would
> cook to a dark colour at that temp :-) Like your
> morning toast.
>
> Imagine how long such a processor
> would last at 25C. Why... forever...
>
>    Paul
I can confirm that this is exactly how electronics is.

In general modern resistors, non electrolytic capacitors and
coils/chokes do not age. Chip, especially chips run hot, do. So do fans.
Running chips cool should net you 30+ years of life.

--
In todays liberal progressive conflict-free education system, everyone
gets full Marx.

On 13/03/2023 10:04, Fredxx wrote:

> Old cars are far easier to keep going than new. Perhaps the greatest
> leap forward in reliability was electronic ignition. Everything else has
> complicated thing to the point that some faults are near impossible to
> repair, especially some intermittent issues.

I suggest you watch some of the earlier Youtube "Rainman Ray" videos
when he worked for a franchise tyre/oil/repair business. Many of his
videos show him diagnosing faults by way of the multitude of the
electronic sensors to a point "where he didn't have to fire the parts
cannon". His videos do show a (great) level of skill in knowing how a
car works and him not just blindly following what the computer says. Not
only does he explain what he is doing and why he ignores the red herring
routes to diagnostics but also shows the fix to the car(s).

For the past 3 months or so many of his videos have been about setting
up his own business with less content showing him using professional OBD
tools to diagnose faults.

In my experience modern cars (of any age) are a lot more reliable than
the cars of the past and in the main just as easy to work on if things
do go wrong. In fact these days you can probably easily find a "how to"
video to fix items on a car and a many forums on the web where you can
discuss the problem, how to fix and the possible pitfalls - much better
than the Haynes manuals. The following possibly shows how frustrating it
was to work on an old car
https://tinyurl.com/2j57j6pw

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 14/03/2023 09:43, alan_m wrote:
> On 13/03/2023 10:04, Fredxx wrote:
>
>> Old cars are far easier to keep going than new. Perhaps the greatest
>> leap forward in reliability was electronic ignition. Everything else
>> has complicated thing to the point that some faults are near
>> impossible to repair, especially some intermittent issues.
>
> I suggest you watch some of the earlier Youtube "Rainman Ray" videos
> when he worked for a franchise tyre/oil/repair business. Many of his
> videos show him diagnosing faults by way of the multitude of the
> electronic sensors to a point "where he didn't have to fire the parts
> cannon". His videos do show a (great) level of skill in knowing how a
> car works and him not just blindly following what the computer says. Not
> only does he explain what he is doing and why he ignores the red herring
> routes to diagnostics but also shows the fix to the car(s).
>
> For the past 3 months or so many of his videos have been about setting
> up his own business with less content showing him using professional OBD
> tools to diagnose faults.
>
"Diagnose Dan" is the man who really knows his computers.

Watching both of them has given me a very good general understanding of
engine management system, at least so far as the number of sensors
involved and what happens when they fail, and a horror of modern
European cars with canbus and half a dozen computers to run the
suspension, the brakes, the climate control the engine,m the
transmission, the door locks and airbags, Arrgghh!

Unfortunately it is all beyond the average grease monkey's intellect, so
they just replace parts at random.

Which is why I got a basic OBD2 scanner. I reckon I will be better at
diagnosing 'warning light; issues than the person I take it to

> In my experience modern cars (of any age) are a lot more reliable than
> the cars of the past and in the main just as easy to work on if things
> do go wrong. In fact these days you can probably easily find a "how to"
> video to fix items on a car and a many forums on the web where you can
> discuss the problem, how to fix and the possible pitfalls - much better
> than the Haynes manuals.
Yes. I remember my first electronic ignition fuel injected car, I bought
to commute to Brussels. An Opel Manta 2000. It simply never went wrong.
No blocked carb jets, because you had to have fuel filters in an
injected car. etc.

The following possibly shows how frustrating it
> was to work on an old car
> https://tinyurl.com/2j57j6pw
>
>

--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

On 14/03/2023 09:36, The Natural Philosopher wrote:
> On 13/03/2023 23:33, Cursitor Doom wrote:
>>> Yesp!  Modern, very complex, cars are*way*  more reliable than those
>>> of decades ago.  Well designed electronics is amazingly reliable.
>
>> They're "amazingly reliable" for the first few years, but I can tell
>> you from very extensive first hand experience that vintage electronics
>> age just the same as everything else. And the more complex they are,
>> the harder it becomes to trace the fault and fix it - and that may
>> become next to impossible when the manufacturer has used custom chips
>> had short production runs.
>
> Vintage electronics are, by definition, not very complex.
> Custom chips only appeared in the 90s really.
>

Depends on application. Not sure when Ferranti started producing ULA but
I believe in the 1970's they were widely used in Cameras.

In home computers, in the 1980's the Ferranti ULA was used in the BBC B,
Sinclair Spectrum and QL which can make repairing these challenging.

This technology led to the development of the ARM CPU as the experience
gained designing the BBC B enable the team to understand high level
logic design....

Dave

On 14/03/2023 09:36, The Natural Philosopher wrote:
> On 13/03/2023 23:33, Cursitor Doom wrote:
>>> Yesp!  Modern, very complex, cars are*way*  more reliable than those
>>> of decades ago.  Well designed electronics is amazingly reliable.
>
>> They're "amazingly reliable" for the first few years, but I can tell
>> you from very extensive first hand experience that vintage electronics
>> age just the same as everything else. And the more complex they are,
>> the harder it becomes to trace the fault and fix it - and that may
>> become next to impossible when the manufacturer has used custom chips
>> had short production runs.
>
> Vintage electronics are, by definition, not very complex.
> Custom chips only appeared in the 90s really.

Pretty much every 80s era micro had a level of custom chippery... Many
used applications specific mask programmed gate arrays (usually made by
Ferranti) to massively cut down the amount of glue logic for address
decoding (even the ZX81 had one - eliminating large numbers of 74 series
logic chips from the ZX80 (overall chip count fell from something like
24 to 6)). Anything with more than rudimentary graphics or sound usually
sported custom chips for that.

Commodore owned a complete semiconductor fab company by virtue of buying
MOS Technology[1] and so made heavy use of custom chips for their video
controllers, sound chips, IO chips, and even custom CPUs (like 6510 in
C64, 8502 in C128).

By the time you got to the mid 80s, and the start of the 16 bit era,
machines like the Amiga were festooned with very sophisticated custom
chips that handled every aspect of the machines performance and gave it
performance levels (particularly graphics, sound, and IO) far in excess
of what you could expect by looking at the CPU specs alone.

[1] They got Chuck Peddle into the bargain!

By the mid 80s you also had Acorn designing their own custom CPU (and we
all probably now own a bunch of their descendants!)

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

On 13/03/2023 23:50, Rod Speed wrote:
> On Mon, 13 Mar 2023 21:04:20 +1100, Fredxx <fredxx@spam.uk> wrote:
>
>> On 12/03/2023 20:51, Chris Green wrote:
>>> Cursitor Doom <cd@notformail.com> wrote:
>>>> On Sat, 11 Mar 2023 15:30:11 -0800 (PST), Animal <tabbypurr@gmail.com>
>>>> wrote:
>>>>
>>>>> On Saturday, 11 March 2023 at 15:51:41 UTC, Rob Morley wrote:
>>>>>> On Sat, 11 Mar 2023 10:26:47 -0000
>>>>>> "Brian Gaff" <brian...@gmail.com> wrote:
>>>>>>
>>>>>>> So, what is the basic difference from the way it works. To me
>>>>>>> from my
>>>>>>> old school days, when I could see, you are basically heating
>>>>>>> stuff up
>>>>>>> and using the welding rod to basically brace it as you want it to
>>>>>>> be.
>>>>>>>
>>>>>> Indeed, basically hot glue for metal, but that's done in different
>>>>>> ways. If we stick (no pun intended) to electric arc welding then you
>>>>>> can supply the heating current through a regular transformer at mains
>>>>>> frequency, or using semiconductors that rectify and switch the
>>>>>> incoming
>>>>>> AC mains in the same way as a switched-mode PSU; this uses a smaller
>>>>>> transformer at higher frequency and efficiency, so it's typically
>>>>>> lighter and more compact with better duty cycle than a traditional
>>>>>> transformer machine. It also allows fine automatic control of the
>>>>>> output
>>>>>> current leading to a more stable arc, and may also support multi-mode
>>>>>> processes so one machine can handle MIG, AC/DC TIG and stick welding.
>>>>>> Also the increasing cost of copper and the decreasing cost of IGBT as
>>>>>> the technology has matured favours inverter machines.
>>>>>>
>>>>>> TLDR:
>>>>>> Inverter welder is more luggable, better arc control but a buzz
>>>>>> box is
>>>>>> likely to survive longer esp. in harsh conditions because it's so
>>>>>> simple.
>>>>>
>>>>> Age & quality are also fairly big factors. An old Sip or Oxford should
>>>> be reliable, a new invertor thing is to often chinesium junk.
>>>>
>>>> That is a major consideration, in fact. The complexity of some of
>>>> these newer inverter welders renders them less reliable overall than
>>>> the old traditional Oxfords and Olympic oil-cooled transformer types
>>>> which just soldier on and on over decades without issue. My 320 amp
>>>> oil-cooled jobbie will be 50 years old this year and still functions
>>>> like the day it was made. Will we be able to say the same for even the
>>>> best inverter types produced today? Nope!
>>>  Yesp!  Modern, very complex, cars are *way* more reliable than those
>>> of decades ago.  Well designed electronics is amazingly reliable.  I
>>> guess the underlying reason is that computers need 'amazingly
>>> reliable' electronics to be at all viable and we really do have a lot
>>> of computers that 'just work'.
>
>> Old cars are far easier to keep going than new.
>
> BULLSHIT.
>
>> Perhaps the greatest leap forward in reliability was electronic
>> ignition. Everything else has complicated thing to the point that some
>> faults are near impossible to repair, especially some intermittent
>> issues.
>
> BULLSHIT.
>
>> The last car I know that was written off from a repair POV was due to
>> a faulty ECU.
>
> More bullshit with accidents
>
>> Even electronics ICs are designed to last a number of years.
>
> BULLSHIT.

Then you've never been involved in chip design. I have.

>> By way of example, tracks are sized in ICs according to potential
>> electromigration failure.  https://en.wikipedia.org/wiki/Electromigration

Yep, you didn't say bullshit to that. Are you feeling ok?

On 14/03/2023 07:47, Paul wrote:
> On 3/13/2023 7:50 PM, Rod Speed wrote:
>> On Mon, 13 Mar 2023 21:04:20 +1100, Fredxx <fredxx@spam.uk> wrote:
>>
>>> Even electronics ICs are designed to last a number of years.
>>
>> BULLSHIT.
>
> If you read enough IBM documentation, this value is "100,000 hours".
>
> We did not use such a metric in our fab. The electromigration
> frequency was just "X", and there was no qualifying "for 100,000 hour
> life".
> Whatever our number was, it wasn't in print. Maybe our reference
> point was in some separate generic reliability document
> I never saw. IBM likes to put that reference figure in
> documentation.
>
> But this is a reference point, for technology choices.
> It basically says, the target most of the time, is
> 100,000 hours minimum, when there is a discussion about
> potential things affecting reliability (max frequency).
> It does not mean they go about ruining things on purpose
> to make the characteristic 100,000. It's just a point
> selected, so you can compare two things at the 100,000 point,
> for their performance.
>
> The customer designing integrated circuits in that fab,
> does not desire the chip to die precisely at 100,000 hours.
>
> If you run a CMOS chip at 135C, the dopant migration might
> make it last 100,000 hours, but the datasheet tells you to
> run it no higher than 100C die temp. And then Arrhenius
> (curve fit), tells you how many million hours it will last.
>
> A chip can last a lot longer than that.
>
> If loose chlorine pollution happens to be inside the
> molded plastic IC package, the IC might only last a year or two.
> IBM traced a case like this, to the usage of a marker
> pen to mark bad die during wafer-sort. (That's where
> you do an ICCC test while probing die sites before the
> wafer gets scribed.)
>
> It's even possible they don't do
> wafer sort any more, and just package it all, and
> that's where bags of 555 timers with a dead short
> between the legs, come from :-) If there was a wafer
> sort for quiescent current, it would have tossed those
> die. But the ICCC test was only really a great idea,
> when CMOS was 3u. At 65nm, there is enough leakage,
> the quiescent current is not a good enough indicator
> of chip quality. You might have to run test vectors
> instead. And packaged parts are likely easier to cool,
> for the high power ones. (Like the ones with a thermal
> slug on the bottom.)
>
> *******
>
> There is one processor, which is rated for 300C.
> But for only 1000 hours :-) This is a processor
> sent down boreholes, like for an oil exploratory hole.
> They characterize at that temperature, because a
> major customer asked them to. There is no industry
> standard for 300C integrated circuits.

I have a friend working on this field and some modules last hours in
their environment, long enough to fulfil their purpose.

> Mil spec
> is the most stringent "widely seen" point. I would
> think your little printed circuit board would
> cook to a dark colour at that temp :-) Like your
> morning toast.

Some of the automotive temperature specs are pretty tough. Why some ECUs
use an alumina substrate. Not sure if they still are?

> Imagine how long such a processor
> would last at 25C. Why... forever...
>
>    Paul

On 14/03/2023 09:43, alan_m wrote:
> On 13/03/2023 10:04, Fredxx wrote:
>
>> Old cars are far easier to keep going than new. Perhaps the greatest
>> leap forward in reliability was electronic ignition. Everything else
>> has complicated thing to the point that some faults are near
>> impossible to repair, especially some intermittent issues.
>
> I suggest you watch some of the earlier Youtube "Rainman Ray" videos
> when he worked for a franchise tyre/oil/repair business. Many of his
> videos show him diagnosing faults by way of the multitude of the
> electronic sensors to a point "where he didn't have to fire the parts
> cannon". His videos do show a (great) level of skill in knowing how a
> car works and him not just blindly following what the computer says. Not
> only does he explain what he is doing and why he ignores the red herring
> routes to diagnostics but also shows the fix to the car(s).
>
> For the past 3 months or so many of his videos have been about setting
> up his own business with less content showing him using professional OBD
> tools to diagnose faults.
>
> In my experience modern cars (of any age) are a lot more reliable than
> the cars of the past and in the main just as easy to work on if things
> do go wrong. In fact these days you can probably easily find a "how to"
> video to fix items on a car and a many forums on the web where you can
> discuss the problem, how to fix and the possible pitfalls - much better
> than the Haynes manuals. The following possibly shows how frustrating it
> was to work on an old car
> https://tinyurl.com/2j57j6pw

When I have time and in the mood I do watch his videos. I also attend a
couple of forums and it's a common story where a garage may or may not
have fault codes and the parts cannon gets used, where each time the
original fault returns.

Most of these failures were difficult to trace. My point was the
simplicity of older cars. Where say an alternator is a single entity,
and not controlled by an ECU. EGRs are another common failure.
Carburation was by a cheap single component.

All the new fangled parts are there for good reason, to improve economy
and emissions, however they add complexity and reduce reliability to suit.

In terms of access, I could get an engine and gearbox out of a Ford
Cortina in 40 minutes, I suspect a pro in much less time. The book time
for a 15 year old Mondeo clutch change is 8 hours. It took me 2 days. As
a result the Mondeo becomes more valuable as scrap for the average guy.

On 14/03/2023 09:58, The Natural Philosopher wrote:
> On 14/03/2023 09:43, alan_m wrote:
>> On 13/03/2023 10:04, Fredxx wrote:
>>
>>> Old cars are far easier to keep going than new. Perhaps the greatest
>>> leap forward in reliability was electronic ignition. Everything else
>>> has complicated thing to the point that some faults are near
>>> impossible to repair, especially some intermittent issues.
>>
>> I suggest you watch some of the earlier Youtube "Rainman Ray" videos
>> when he worked for a franchise tyre/oil/repair business. Many of his
>> videos show him diagnosing faults by way of the multitude of the
>> electronic sensors to a point "where he didn't have to fire the parts
>> cannon". His videos do show a (great) level of skill in knowing how a
>> car works and him not just blindly following what the computer says.
>> Not only does he explain what he is doing and why he ignores the red
>> herring routes to diagnostics but also shows the fix to the car(s).
>>
>> For the past 3 months or so many of his videos have been about setting
>> up his own business with less content showing him using professional
>> OBD tools to diagnose faults.
>>
> "Diagnose Dan" is the man who really knows his computers.
>
> Watching both of them has given me a very good general understanding of
> engine management system, at least so far as the number of sensors
> involved and what happens when they fail, and a horror of modern
> European cars with canbus and half a dozen computers to run the
> suspension, the brakes, the climate control the engine,m the
> transmission, the door locks and airbags, Arrgghh!
>
> Unfortunately it is all beyond the average grease monkey's intellect, so
> they just replace parts at random.
>
> Which is why I got a basic OBD2 scanner. I reckon I will be better at
> diagnosing 'warning light; issues than the person I take it to

It's one reason I like Fords, as Forscan is mainly free and is a complex
scanner than can also do key coding.

As a car ages, some scanner compatible with the car will generally
become available, if only a knock-off from China.

>> In my experience modern cars (of any age) are a lot more reliable than
>> the cars of the past and in the main just as easy to work on if things
>> do go wrong. In fact these days you can probably easily find a "how
>> to" video to fix items on a car and a many forums on the web where you
>> can discuss the problem, how to fix and the possible pitfalls - much
>> better than the Haynes manuals.
> Yes. I remember my first electronic ignition fuel injected car, I bought
> to commute to Brussels. An Opel Manta 2000. It simply never went wrong.
> No blocked carb jets, because you had to have fuel filters in an
> injected car. etc.
>
>
>
> The following possibly shows how frustrating it
>> was to work on an old car
>> https://tinyurl.com/2j57j6pw

LOL but even then it was largely down to having the right tools. They
have come down in price in real terms and and the cost can easily be
justified in terms of saving compared to garage labour costs.

On 13/03/2023 23:33, Cursitor Doom wrote:
> On Sun, 12 Mar 2023 20:51:49 +0000, Chris Green <cl@isbd.net> wrote:
>
>> Cursitor Doom <cd@notformail.com> wrote:
>>> On Sat, 11 Mar 2023 15:30:11 -0800 (PST), Animal <tabbypurr@gmail.com>
>>> wrote:
>>>
>>>> On Saturday, 11 March 2023 at 15:51:41 UTC, Rob Morley wrote:
>>>>> On Sat, 11 Mar 2023 10:26:47 -0000
>>>>> "Brian Gaff" <brian...@gmail.com> wrote:
>>>>>
>>>>>> So, what is the basic difference from the way it works. To me from my
>>>>>> old school days, when I could see, you are basically heating stuff up
>>>>>> and using the welding rod to basically brace it as you want it to be.
>>>>>>
>>>>> Indeed, basically hot glue for metal, but that's done in different
>>>>> ways. If we stick (no pun intended) to electric arc welding then you
>>>>> can supply the heating current through a regular transformer at mains
>>>>> frequency, or using semiconductors that rectify and switch the incoming
>>>>> AC mains in the same way as a switched-mode PSU; this uses a smaller
>>>>> transformer at higher frequency and efficiency, so it's typically
>>>>> lighter and more compact with better duty cycle than a traditional
>>>>> transformer machine. It also allows fine automatic control of the output
>>>>> current leading to a more stable arc, and may also support multi-mode
>>>>> processes so one machine can handle MIG, AC/DC TIG and stick welding.
>>>>> Also the increasing cost of copper and the decreasing cost of IGBT as
>>>>> the technology has matured favours inverter machines.
>>>>>
>>>>> TLDR:
>>>>> Inverter welder is more luggable, better arc control but a buzz box is
>>>>> likely to survive longer esp. in harsh conditions because it's so
>>>>> simple.
>>>>
>>>> Age & quality are also fairly big factors. An old Sip or Oxford should
>>> be reliable, a new invertor thing is to often chinesium junk.
>>>
>>> That is a major consideration, in fact. The complexity of some of
>>> these newer inverter welders renders them less reliable overall than
>>> the old traditional Oxfords and Olympic oil-cooled transformer types
>>> which just soldier on and on over decades without issue. My 320 amp
>>> oil-cooled jobbie will be 50 years old this year and still functions
>>> like the day it was made. Will we be able to say the same for even the
>>> best inverter types produced today? Nope!
>>
>> Yesp! Modern, very complex, cars are *way* more reliable than those
>> of decades ago. Well designed electronics is amazingly reliable.
>
> They're "amazingly reliable" for the first few years, but I can tell
> you from very extensive first hand experience that vintage electronics
> age just the same as everything else. And the more complex they are,
> the harder it becomes to trace the fault and fix it - and that may
> become next to impossible when the manufacturer has used custom chips
> had short production runs.

Vintage electronics is an oxy-moron. The only vintage electronics in one
vehicle I have is the radio!

On 14/03/2023 08:16, Paul wrote:
> On 3/12/2023 2:03 PM, Cursitor Doom wrote:
>> On Sat, 11 Mar 2023 15:30:11 -0800 (PST), Animal <tabbypurr@gmail.com>
>> wrote:
>>
>>> On Saturday, 11 March 2023 at 15:51:41 UTC, Rob Morley wrote:
>>>> On Sat, 11 Mar 2023 10:26:47 -0000
>>>> "Brian Gaff" <brian...@gmail.com> wrote:
>>>>
>>>>> So, what is the basic difference from the way it works. To me from my
>>>>> old school days, when I could see, you are basically heating stuff up
>>>>> and using the welding rod to basically brace it as you want it to be.
>>>>>
>>>> Indeed, basically hot glue for metal, but that's done in different
>>>> ways. If we stick (no pun intended) to electric arc welding then you
>>>> can supply the heating current through a regular transformer at mains
>>>> frequency, or using semiconductors that rectify and switch the incoming
>>>> AC mains in the same way as a switched-mode PSU; this uses a smaller
>>>> transformer at higher frequency and efficiency, so it's typically
>>>> lighter and more compact with better duty cycle than a traditional
>>>> transformer machine. It also allows fine automatic control of the
>>>> output
>>>> current leading to a more stable arc, and may also support multi-mode
>>>> processes so one machine can handle MIG, AC/DC TIG and stick welding.
>>>> Also the increasing cost of copper and the decreasing cost of IGBT as
>>>> the technology has matured favours inverter machines.
>>>>
>>>> TLDR:
>>>> Inverter welder is more luggable, better arc control but a buzz box is
>>>> likely to survive longer esp. in harsh conditions because it's so
>>>> simple.
>>>
>>> Age & quality are also fairly big factors. An old Sip or Oxford
>>> should be reliable, a new invertor thing is to often chinesium junk.
>>
>> That is a major consideration, in fact. The complexity of some of
>> these newer inverter welders renders them less reliable overall than
>> the old traditional Oxfords and Olympic oil-cooled transformer types
>> which just soldier on and on over decades without issue. My 320 amp
>> oil-cooled jobbie will be 50 years old this year and still functions
>> like the day it was made. Will we be able to say the same for even the
>> best inverter types produced today? Nope!
>>
>
> Do the circuit analysis, and spot the weakness.
>
>
> https://www.homemade-circuits.com/wp-content/uploads/2014/07/welding2Bpower2Bsupply.png
>
> To me, the biggest weakness is "noise on rails". A large enough transient
> on mains could damage the switching transistors, but then half the
> stuff in your house would also be blown to hell and back if that
> happened.
>
> That circuit should have some filtering before the full wave bridge, to
> stop switching noise from going back onto mains.
>
> Where the design has an advantage, is the transformer does not
> have to be as big, at the switching frequency used.
>
> That circuit has three snubber networks, and it has series
> resistors on the switching transistor gates to prevent "punchthru".
> Transistors with 3000pF gate capacitance, a couple amperes
> of current flows from the pre-drive, into the gate, and
> this can burn a hole in the gate, if the peak current is too high.
> The circuit has the necessary series resistors to reduce the peak
> current value.
>
> The dot on one of the transformer windings , is the wrong way round :-)

Are you sure? The transistors are wired in series with the transformer,
it's not a push-pull affair as there's no centre tap or full or half
bridge. I assumed to halve the voltage across transistor when it's not
conducting?

> There are some circuit functions, that are notorious for failure,
> such as variable speed motor drive. But I don't know the reason
> for that.
>
>    Paul

On 3/14/2023 8:09 AM, Fredxx wrote:
> On 14/03/2023 08:16, Paul wrote:
>> The dot on one of the transformer windings , is the wrong way round :-)
>
> Are you sure? The transistors are wired in series with the transformer, it's not a push-pull affair as there's no centre tap or full or half bridge. I assumed to halve the voltage across transistor when it's not conducting?
>
I can't really figure out what they're doing there.

As it would seem if you just had the low side drive,
that would be enough, and the low side has the
feedback to the flyback controller (presumably
for some sort of current monitoring).

The diode at the top, shows a zener symbol but it's a
fast rectifier diode with a 600 volt rating. Clamping
the low side drive to no more than a diode drop above
positive rail.

When I did a flyback here, it was push-pull so maybe
that's why I'm looking for push-pull.

Paul

On 14/03/2023 13:19, Paul wrote:
> On 3/14/2023 8:09 AM, Fredxx wrote:
>> On 14/03/2023 08:16, Paul wrote:
>>> The dot on one of the transformer windings , is the wrong way round :-)
>>
>> Are you sure? The transistors are wired in series with the
>> transformer, it's not a push-pull affair as there's no centre tap or
>> full or half bridge. I assumed to halve the voltage across transistor
>> when it's not conducting?
>>
> I can't really figure out what they're doing there.
>
> As it would seem if you just had the low side drive,
> that would be enough, and the low side has the
> feedback to the flyback controller (presumably
> for some sort of current monitoring).
>
> The diode at the top, shows a zener symbol but it's a
> fast rectifier diode with a 600 volt rating. Clamping
> the low side drive to no more than a diode drop above
> positive rail.
>
> When I did a flyback here, it was push-pull so maybe
> that's why I'm looking for push-pull.

I have seen a power supply many years ago using the same topology. It
seemed nonsense to use 2 lower specced transistors then one higher,
given the additional complexity. However the economics must have
dictated this. Perhaps their inventory only included components for the
110/120V market where just the one was fitted?

A full H-bridge gives you a greater transformer efficiency, as well as
easy clamping of spikes to each rail.

To be fair for the design, there shouldn't be a route for positive
spikes to be transferred to the input mains through the bridge
rectifier. Power can only pass into the welder, not back out[1].

[1] I am aware there is a finite diode turn off time, but the energy
associated with that should be pretty low.

Paul <nospam@needed.invalid> wrote
> Rod Speed wrote
>> Fredxx <fredxx@spam.uk> wrote

>>> Even electronics ICs are designed to last a number of years.

>> BULLSHIT.

> If you read enough IBM documentation, this value is "100,000 hours".

IBM does fuck all fab that matters anymore.

> We did not use such a metric in our fab.

Neither does anyone else that matters.

> The electromigration

Isnt what determines the life of most electronic ICs

> frequency was just "X", and there was no qualifying "for 100,000 hour
> life".

> Whatever our number was, it wasn't in print. Maybe our reference
> point was in some separate generic reliability document
> I never saw. IBM likes to put that reference figure in
> documentation.

> But this is a reference point, for technology choices.
> It basically says, the target most of the time, is
> 100,000 hours minimum, when there is a discussion about
> potential things affecting reliability (max frequency).
> It does not mean they go about ruining things on purpose
> to make the characteristic 100,000. It's just a point
> selected, so you can compare two things at the 100,000 point,
> for their performance.

> The customer designing integrated circuits in that fab,
> does not desire the chip to die precisely at 100,000 hours.

> If you run a CMOS chip at 135C, the dopant migration might
> make it last 100,000 hours, but the datasheet tells you to
> run it no higher than 100C die temp. And then Arrhenius
> (curve fit), tells you how many million hours it will last.

> A chip can last a lot longer than that.

Which is what I meant.

> If loose chlorine pollution happens to be inside the
> molded plastic IC package, the IC might only last a year or two.
> IBM traced a case like this, to the usage of a marker
> pen to mark bad die during wafer-sort. (That's where
> you do an ICCC test while probing die sites before the
> wafer gets scribed.)
>
> It's even possible they don't do
> wafer sort any more, and just package it all, and
> that's where bags of 555 timers with a dead short
> between the legs, come from :-) If there was a wafer
> sort for quiescent current, it would have tossed those
> die. But the ICCC test was only really a great idea,
> when CMOS was 3u. At 65nm, there is enough leakage,
> the quiescent current is not a good enough indicator
> of chip quality. You might have to run test vectors
> instead. And packaged parts are likely easier to cool,
> for the high power ones. (Like the ones with a thermal
> slug on the bottom.)
>
> *******
>
> There is one processor, which is rated for 300C.
> But for only 1000 hours :-) This is a processor
> sent down boreholes, like for an oil exploratory hole.
> They characterize at that temperature, because a
> major customer asked them to. There is no industry
> standard for 300C integrated circuits. Mil spec
> is the most stringent "widely seen" point. I would
> think your little printed circuit board would
> cook to a dark colour at that temp :-) Like your
> morning toast.
>
> Imagine how long such a processor
> would last at 25C. Why... forever...
>
> Paul

On Tue, 14 Mar 2023 22:32:14 +1100, Fredxx <fredxx@spam.uk> wrote:

> On 13/03/2023 23:50, Rod Speed wrote:
>> On Mon, 13 Mar 2023 21:04:20 +1100, Fredxx <fredxx@spam.uk> wrote:
>>
>>> On 12/03/2023 20:51, Chris Green wrote:
>>>> Cursitor Doom <cd@notformail.com> wrote:
>>>>> On Sat, 11 Mar 2023 15:30:11 -0800 (PST), Animal
>>>>> <tabbypurr@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> On Saturday, 11 March 2023 at 15:51:41 UTC, Rob Morley wrote:
>>>>>>> On Sat, 11 Mar 2023 10:26:47 -0000
>>>>>>> "Brian Gaff" <brian...@gmail.com> wrote:
>>>>>>>
>>>>>>>> So, what is the basic difference from the way it works. To me
>>>>>>>> from my
>>>>>>>> old school days, when I could see, you are basically heating
>>>>>>>> stuff up
>>>>>>>> and using the welding rod to basically brace it as you want it to
>>>>>>>> be.
>>>>>>>>
>>>>>>> Indeed, basically hot glue for metal, but that's done in different
>>>>>>> ways. If we stick (no pun intended) to electric arc welding then
>>>>>>> you
>>>>>>> can supply the heating current through a regular transformer at
>>>>>>> mains
>>>>>>> frequency, or using semiconductors that rectify and switch the
>>>>>>> incoming
>>>>>>> AC mains in the same way as a switched-mode PSU; this uses a
>>>>>>> smaller
>>>>>>> transformer at higher frequency and efficiency, so it's typically
>>>>>>> lighter and more compact with better duty cycle than a traditional
>>>>>>> transformer machine. It also allows fine automatic control of the
>>>>>>> output
>>>>>>> current leading to a more stable arc, and may also support
>>>>>>> multi-mode
>>>>>>> processes so one machine can handle MIG, AC/DC TIG and stick
>>>>>>> welding.
>>>>>>> Also the increasing cost of copper and the decreasing cost of IGBT
>>>>>>> as
>>>>>>> the technology has matured favours inverter machines.
>>>>>>>
>>>>>>> TLDR:
>>>>>>> Inverter welder is more luggable, better arc control but a buzz
>>>>>>> box is
>>>>>>> likely to survive longer esp. in harsh conditions because it's so
>>>>>>> simple.
>>>>>>
>>>>>> Age & quality are also fairly big factors. An old Sip or Oxford
>>>>>> should
>>>>> be reliable, a new invertor thing is to often chinesium junk.
>>>>>
>>>>> That is a major consideration, in fact. The complexity of some of
>>>>> these newer inverter welders renders them less reliable overall than
>>>>> the old traditional Oxfords and Olympic oil-cooled transformer types
>>>>> which just soldier on and on over decades without issue. My 320 amp
>>>>> oil-cooled jobbie will be 50 years old this year and still functions
>>>>> like the day it was made. Will we be able to say the same for even
>>>>> the
>>>>> best inverter types produced today? Nope!
>>>> Yesp! Modern, very complex, cars are *way* more reliable than those
>>>> of decades ago. Well designed electronics is amazingly reliable. I
>>>> guess the underlying reason is that computers need 'amazingly
>>>> reliable' electronics to be at all viable and we really do have a lot
>>>> of computers that 'just work'.
>>
>>> Old cars are far easier to keep going than new.
>> BULLSHIT.
>>
>>> Perhaps the greatest leap forward in reliability was electronic
>>> ignition. Everything else has complicated thing to the point that some
>>> faults are near impossible to repair, especially some intermittent
>>> issues.
>> BULLSHIT.
>>
>>> The last car I know that was written off from a repair POV was due to
>>> a faulty ECU.
>> More bullshit with accidents
>>
>>> Even electronics ICs are designed to last a number of years.
>> BULLSHIT.
>
> Then you've never been involved in chip design. I have.

You are wrong, as always.

>>> By way of example, tracks are sized in ICs according to potential
>>> electromigration failure.
>>> https://en.wikipedia.org/wiki/Electromigration

On Tue, 14 Mar 2023 22:49:17 +1100, Fredxx <fredxx@spam.uk> wrote:

> On 14/03/2023 09:43, alan_m wrote:
>> On 13/03/2023 10:04, Fredxx wrote:
>>
>>> Old cars are far easier to keep going than new. Perhaps the greatest
>>> leap forward in reliability was electronic ignition. Everything else
>>> has complicated thing to the point that some faults are near
>>> impossible to repair, especially some intermittent issues.
>> I suggest you watch some of the earlier Youtube "Rainman Ray" videos
>> when he worked for a franchise tyre/oil/repair business. Many of his
>> videos show him diagnosing faults by way of the multitude of the
>> electronic sensors to a point "where he didn't have to fire the parts
>> cannon". His videos do show a (great) level of skill in knowing how a
>> car works and him not just blindly following what the computer says.
>> Not only does he explain what he is doing and why he ignores the red
>> herring routes to diagnostics but also shows the fix to the car(s).
>> For the past 3 months or so many of his videos have been about setting
>> up his own business with less content showing him using professional
>> OBD tools to diagnose faults.
>> In my experience modern cars (of any age) are a lot more reliable than
>> the cars of the past and in the main just as easy to work on if things
>> do go wrong. In fact these days you can probably easily find a "how to"
>> video to fix items on a car and a many forums on the web where you can
>> discuss the problem, how to fix and the possible pitfalls - much better
>> than the Haynes manuals. The following possibly shows how frustrating
>> it was to work on an old car
>> https://tinyurl.com/2j57j6pw
>
>
> When I have time and in the mood I do watch his videos. I also attend a
> couple of forums and it's a common story where a garage may or may not
> have fault codes and the parts cannon gets used, where each time the
> original fault returns.
>
> Most of these failures were difficult to trace. My point was the
> simplicity of older cars. Where say an alternator is a single entity,
> and not controlled by an ECU. EGRs are another common failure.
> Carburation was by a cheap single component.
>
> All the new fangled parts are there for good reason, to improve economy
> and emissions, however they add complexity

Yes.

> and reduce reliability to suit.

Nope.

> In terms of access, I could get an engine and gearbox out of a Ford
> Cortina in 40 minutes, I suspect a pro in much less time. The book time
> for a 15 year old Mondeo clutch change is 8 hours. It took me 2 days. As
> a result the Mondeo becomes more valuable as scrap for the average guy.

Hardly anyone scraps their current car when it needs a clutch change.

On 15/03/2023 05:11, Rod Speed wrote:
> On Tue, 14 Mar 2023 22:49:17 +1100, Fredxx <fredxx@spam.uk> wrote:
>
>> On 14/03/2023 09:43, alan_m wrote:
>>> On 13/03/2023 10:04, Fredxx wrote:
>>>
>>>> Old cars are far easier to keep going than new. Perhaps the greatest
>>>> leap forward in reliability was electronic ignition. Everything else
>>>> has complicated thing to the point that some faults are near
>>>> impossible to repair, especially some intermittent issues.
>>>  I suggest you watch some of the earlier Youtube "Rainman Ray" videos
>>> when he worked for a franchise tyre/oil/repair business. Many of his
>>> videos show him diagnosing faults by way of the multitude of the
>>> electronic sensors to a point "where he didn't have to fire the parts
>>> cannon". His videos do show a (great) level of skill in knowing how a
>>> car works and him not just blindly following what the computer says.
>>> Not only does he explain what he is doing and why he ignores the red
>>> herring routes to diagnostics but also shows the fix to the car(s).
>>>  For the past 3 months or so many of his videos have been about
>>> setting up his own business with less content showing him using
>>> professional OBD tools to diagnose faults.
>>>  In my experience modern cars (of any age) are a lot more reliable
>>> than the cars of the past and in the main just as easy to work on if
>>> things do go wrong. In fact these days you can probably easily find a
>>> "how to" video to fix items on a car and a many forums on the web
>>> where you can discuss the problem, how to fix and the possible
>>> pitfalls - much better than the Haynes manuals. The following
>>> possibly shows how frustrating it was to work on an old car
>>> https://tinyurl.com/2j57j6pw
>>
>>
>> When I have time and in the mood I do watch his videos. I also attend
>> a couple of forums and it's a common story where a garage may or may
>> not have fault codes and the parts cannon gets used, where each time
>> the original fault returns.
>>
>> Most of these failures were difficult to trace. My point was the
>> simplicity of older cars. Where say an alternator is a single entity,
>> and not controlled by an ECU. EGRs are another common failure.
>> Carburation was by a cheap single component.
>>
>> All the new fangled parts are there for good reason, to improve
>> economy and emissions, however they add complexity
>
> Yes.
>
>> and reduce reliability to suit.
>
> Nope.
>
>> In terms of access, I could get an engine and gearbox out of a Ford
>> Cortina in 40 minutes, I suspect a pro in much less time. The book
>> time for a 15 year old Mondeo clutch change is 8 hours. It took me 2
>> days. As a result the Mondeo becomes more valuable as scrap for the
>> average guy.
>
> Hardly anyone scraps their current car when it needs a clutch change.

The garage cost of a clutch change or dual mass flywheel on an 18 year
old Mondeo is £1,000, you may get down to £800 if you're lucky.

I can assure you, you can sell the car 'as is' for more than than a car
value with a working clutch less the cost of fitting.

Perhaps you were more familiar with UK car prices you wouldn't look so
silly. Perhaps you also misunderstand the UK colloquial expression "scrap".

On Thu, 16 Mar 2023 00:47:13 +1100, Fredxx <fredxx@spam.uk> wrote:

> On 15/03/2023 05:11, Rod Speed wrote:
>> On Tue, 14 Mar 2023 22:49:17 +1100, Fredxx <fredxx@spam.uk> wrote:
>>
>>> On 14/03/2023 09:43, alan_m wrote:
>>>> On 13/03/2023 10:04, Fredxx wrote:
>>>>
>>>>> Old cars are far easier to keep going than new. Perhaps the greatest
>>>>> leap forward in reliability was electronic ignition. Everything else
>>>>> has complicated thing to the point that some faults are near
>>>>> impossible to repair, especially some intermittent issues.
>>>> I suggest you watch some of the earlier Youtube "Rainman Ray" videos
>>>> when he worked for a franchise tyre/oil/repair business. Many of his
>>>> videos show him diagnosing faults by way of the multitude of the
>>>> electronic sensors to a point "where he didn't have to fire the parts
>>>> cannon". His videos do show a (great) level of skill in knowing how a
>>>> car works and him not just blindly following what the computer says..
>>>> Not only does he explain what he is doing and why he ignores the red
>>>> herring routes to diagnostics but also shows the fix to the car(s).
>>>> For the past 3 months or so many of his videos have been about
>>>> setting up his own business with less content showing him using
>>>> professional OBD tools to diagnose faults.
>>>> In my experience modern cars (of any age) are a lot more reliable
>>>> than the cars of the past and in the main just as easy to work on if
>>>> things do go wrong. In fact these days you can probably easily find a
>>>> "how to" video to fix items on a car and a many forums on the web
>>>> where you can discuss the problem, how to fix and the possible
>>>> pitfalls - much better than the Haynes manuals. The following
>>>> possibly shows how frustrating it was to work on an old car
>>>> https://tinyurl.com/2j57j6pw
>>>
>>>
>>> When I have time and in the mood I do watch his videos. I also attend
>>> a couple of forums and it's a common story where a garage may or may
>>> not have fault codes and the parts cannon gets used, where each time
>>> the original fault returns.
>>>
>>> Most of these failures were difficult to trace. My point was the
>>> simplicity of older cars. Where say an alternator is a single entity,
>>> and not controlled by an ECU. EGRs are another common failure.
>>> Carburation was by a cheap single component.
>>>
>>> All the new fangled parts are there for good reason, to improve
>>> economy and emissions, however they add complexity
>> Yes.
>>
>>> and reduce reliability to suit.
>> Nope.
>>
>>> In terms of access, I could get an engine and gearbox out of a Ford
>>> Cortina in 40 minutes, I suspect a pro in much less time. The book
>>> time for a 15 year old Mondeo clutch change is 8 hours. It took me 2
>>> days. As a result the Mondeo becomes more valuable as scrap for the
>>> average guy.

>> Hardly anyone scraps their current car when it needs a clutch change..

> The garage cost of a clutch change or dual mass flywheel on an 18 year
> old Mondeo is £1,000, you may get down to £800 if you're lucky.

My 73 Golf never needed a new clutch in the 45 years I was using it
and I only replaced that car because I stupidly did nothing about the
known windscreen leak that produced a damp floor after heavy rain
and eventually rusted out the floor and I couldn't be arsed to fix that.

> I can assure you, you can sell the car 'as is' for more than than a car
> value with a working clutch less the cost of fitting.

That's not scrapping the car.

<reams of your shit any 2 year old could leave for dead flushed where it
belongs>

On Tue, 14 Mar 2023 09:43:53 +0000
alan_m <junk@admac.myzen.co.uk> wrote:

> The following possibly shows how frustrating it
> was to work on an old car
> https://tinyurl.com/2j57j6pw

That's what it can seem like until you get used to it - often splashing
on some PlusGas before you start, or applying heat before you round or
break the fasteners will get the job done without drama. And when bolts
break you have extraction methods - my favourite is the weld a nut on
technique but you also have cobalt drill bits and screw extractors and
the taps to clean up the threads afterwards, and helicoils if that
doesn't work out.