In message <inf5leF3igqU1@mid.individual.net>, Roger Mills
<watt.tyler@gmail.com> writes
>On 10/08/2021 10:49, Ian Jackson wrote:
>> In message <ineueqF23i5U1@mid.individual.net>, Roger Mills
>><watt.tyler@gmail.com> writes
>>> On 10/08/2021 09:13, Tony Gamble wrote:
>>>>
>>>>>
>>>>> It brings up a line of text on the screen saying "Start Adjustment
>>>>>Menu" - whatever that means. I can't then get it to do anything
>>>>>else but at least the screen can't be entirely dead.
>>>>>
>>>>  That sounds optimistic.
>>>>  I have not been through the whole of this thread but have you
>>>>googled  for a service manual. I know this is not the precise model
>>>>that you own  but it may offer some starter suggestions.
>>>>
>>>> https://www.manualslib.com/manual/1905110/Panasonic-Tx-40ds500b.html?pa
>>>> ge=2#manual    It did refer to the keys you used on your remote so
>>>>it might not be too  different for the next step.
>>>
>>> Yes, I've downloaded the correct service manual - but it seems to
>>>assume that the OSD is working - which it ain't, apart from this
>>>single line of text "Start Adjustment Menu"
>> Does the set have a usable video output - something that could be
>>looked at (by whatever means) on something external?
>
>Do you mean via Scart or HDMI etc.?

Anything you could use.

> It does potentially have these but I wouldn't expect to see anything
>on them because it hasn't properly got past the power on stage.

It was just a suggestion in case the set WAS actually working, but not
displaying on its own screen.
--
Ian

On 10/08/2021 12:42, David Woolley wrote:
> On 10/08/2021 11:46, R. Mark Clayton wrote:
>> Mine is a Toshiba, it does do that, then the light goes solid green
>> and it starts.  Despite software updates, the set still gets stuck
>> from time to time with a blank screen and the green light flashing,
>> resolved by power cycling.
>
>
> Same for my Toshiba branded Vestel.
>
> (Maybe it it is something to do with global warming as the weather app
> reports hypersonic winds and extreme barometric pressures :-).)

I've lost count of how many times I've power cycled mine - all to no avail!
--
Cheers,
Roger

On 10/08/2021 13:46, Ian Jackson wrote:
> In message <inf5leF3igqU1@mid.individual.net>, Roger Mills
> <watt.tyler@gmail.com> writes
>> On 10/08/2021 10:49, Ian Jackson wrote:
>>> In message <ineueqF23i5U1@mid.individual.net>, Roger Mills
>>> <watt.tyler@gmail.com> writes
>>>> On 10/08/2021 09:13, Tony Gamble wrote:
>>>>>
>>>>>>
>>>>>> It brings up a line of text on the screen saying "Start Adjustment
>>>>>> Menu" - whatever that means. I can't then get it to do anything
>>>>>> else  but at least the screen can't be entirely dead.
>>>>>>
>>>>>  That sounds optimistic.
>>>>>  I have not been through the whole of this thread but have you
>>>>> googled  for a service manual. I know this is not the precise model
>>>>> that you own  but it may offer some starter suggestions.
>>>>>
>>>>> https://www.manualslib.com/manual/1905110/Panasonic-Tx-40ds500b.html?pa
>>>>>
>>>>> ge=2#manual    It did refer to the keys you used on your remote so
>>>>> it  might not be too  different for the next step.
>>>>
>>>> Yes, I've downloaded the correct service manual - but it seems to
>>>> assume that the OSD is working - which it ain't, apart from this
>>>> single line of text "Start Adjustment Menu"
>>>  Does the set have a usable video output - something that could be
>>> looked  at (by whatever means) on something external?
>>
>> Do you mean via Scart or HDMI etc.?
>
> Anything you could use.
>
>> It does potentially have these but I wouldn't expect to see anything
>> on them because it hasn't properly got past the power on stage.
>
> It was just a suggestion in case the set WAS actually working, but not
> displaying on its own screen.

No I'm pretty sure it's not. There's no sound, either.
--
Cheers,
Roger

Roger Mills wrote:
> On 10/08/2021 09:13, Tony Gamble wrote:
>>
>>>
>>> It brings up a line of text on the screen saying "Start Adjustment
>>> Menu" - whatever that means. I can't then get it to do anything else
>>> but at least the screen can't be entirely dead.
>>>
>>
>> That sounds optimistic.
>>
>> I have not been through the whole of this thread but have you googled
>> for a service manual. I know this is not the precise model that you
>> own but it may offer some starter suggestions.
>>
>> https://www.manualslib.com/manual/1905110/Panasonic-Tx-40ds500b.html?page=2#manual
>>
>>
>> It did refer to the keys you used on your remote so it might not be
>> too different for the next step.
>
> Yes, I've downloaded the correct service manual - but it seems to assume
> that the OSD is working - which it ain't, apart from this single line of
> text "Start Adjustment Menu"

I tried a Google on the string, with quotes...

This item is for a plasma set, so should not be used
for an LCD exactly.

http://www.controlcal.com/forum/showthread.php?t=1006

"
"Start Adjustment Menu" message will be displayed
followed by the Service Menu after few seconds.

You should see this as your display:

ADJUST {Picture Adjustment}
WB-ADJUST {White Balance Adjustment}
OPTION {Option Setting}
V-SUS {V-SUS Adjustment}
AGING
SRV-TOOL {Service Tool}
"1" & "2" buttons move through options
"

That appears to be the entry point of the Service Menu.
If a person was servicing the set (TV Repair), then
they would attempt to get there. Your service menu
is not rendering to screen.

There is a second reference here. Last post.

https://www.hifivision.com/threads/solution-to-find-out-panasonic-lcd-usage-hours.32728/

"You have to keep the {Channel -} button on the TV panel and
keep it pressed (do not release). While the above button is
pressed, press {INFO} button 3 times. <=== [Info button on Remote?]

At this point {Channel -} can be released."

[And press Exit to come out of Service Menu]

Another example here, of a Service Menu.

https://lcd-television-repair.com/newsletter/Panasonic_TV_Service_Menu.html

So far, no suggestions for why the Service Menu won't paint.

Paul

In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
> Indeed. But holding V- and pressing 0 (zero) on the remote 3 times
> *does* do something.
>
> It brings up a line of text on the screen saying "Start Adjustment Menu"
> - whatever that means. I can't then get it to do anything else but at
> least the screen can't be entirely dead.

Service mode is operated through the number keys:

Press the 3/4 button to change the adjustment values or function.
Press the 1/2 button to step up/down through the functions and adjustments
Press the numerical button VOLUME (+/-) to change option item.
Press the OK button after each adjustment has been made to store the
required values.

Does this work:

Self Check
Self-check is used to automatically check the bus lines and hexadecimal code
of the TV set. To enter Self-Check mode, keep
pressing the down (-/v) button on the TV set and press the STATUS [i]
button on the remote control. To exit Self Check,
switch off the TV set at the power button.

and you should check the power LED blinking sequence:

Power LED blinking timing chart
1. Subject
Information of LED Flashing timing chart.
2. Contents
When abnormality has occurred the unit, the protection circuit operates and
reset to the stand by mode. At this time, the defective block can be
identified by number of blinking of the Power LED on the front panel of the
unit.

It flashes the LED N times, and then goes off, then N flashes, etc. How
many flashes are there? All point to the main board except where noted:

1=INVERTER_SOS (inverter board)
2=FAN_SOS
3=SOS
4=SUB_F_12V
5=MAIN9V
6=SUB5V (remote receiver board)
7=SUB3.3V
8=MAIN3.3V
9=SOUND_SOS
10=EMERGENCY_SOS

Theo

On 10/08/2021 15:08, Theo wrote:
> In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
>> Indeed. But holding V- and pressing 0 (zero) on the remote 3 times
>> *does* do something.
>>
>> It brings up a line of text on the screen saying "Start Adjustment Menu"
>> - whatever that means. I can't then get it to do anything else but at
>> least the screen can't be entirely dead.
>
> Service mode is operated through the number keys:
>
> Press the 3/4 button to change the adjustment values or function.
> Press the 1/2 button to step up/down through the functions and adjustments
> Press the numerical button VOLUME (+/-) to change option item.
> Press the OK button after each adjustment has been made to store the
> required values.
>
That presupposes that some options are displayed - they aint!
>
>
> Does this work:
>
> Self Check
> Self-check is used to automatically check the bus lines and hexadecimal code
> of the TV set. To enter Self-Check mode, keep
> pressing the down (-/v) button on the TV set and press the STATUS [i]
> button on the remote control. To exit Self Check,
> switch off the TV set at the power button.
>
>
Ditto, can't get there either.

> and you should check the power LED blinking sequence:
>
> Power LED blinking timing chart
> 1. Subject
> Information of LED Flashing timing chart.
> 2. Contents
> When abnormality has occurred the unit, the protection circuit operates and
> reset to the stand by mode. At this time, the defective block can be
> identified by number of blinking of the Power LED on the front panel of the
> unit.
>
> It flashes the LED N times, and then goes off, then N flashes, etc. How
> many flashes are there? All point to the main board except where noted:
>
> 1=INVERTER_SOS (inverter board)
> 2=FAN_SOS
> 3=SOS
> 4=SUB_F_12V
> 5=MAIN9V
> 6=SUB5V (remote receiver board)
> 7=SUB3.3V
> 8=MAIN3.3V
> 9=SOUND_SOS
> 10=EMERGENCY_SOS
>
> Theo
>

The light flashes continuously quite fast, with no pauses. I assume that
means EMERGENCY_SOS - whatever that is!

Incidentally, on P10 of the service manual there is a table of voltages
to check on the A-board. Each one is referenced by a TP No. such as
TP2765. But I can't see anything that obviously looks like test points,
and most of the text on the board is too small to read. How do I find
these points?
--
Cheers,
Roger

On 10/08/2021 14:00, Paul wrote:
> Roger Mills wrote:
>> On 10/08/2021 09:13, Tony Gamble wrote:
>>>
>>>>
>>>> It brings up a line of text on the screen saying "Start Adjustment
>>>> Menu" - whatever that means. I can't then get it to do anything else
>>>> but at least the screen can't be entirely dead.
>>>>
>>>
>>> That sounds optimistic.
>>>
>>> I have not been through the whole of this thread but have you googled
>>> for a service manual. I know this is not the precise model that you
>>> own but it may offer some starter suggestions.
>>>
>>> https://www.manualslib.com/manual/1905110/Panasonic-Tx-40ds500b.html?page=2#manual
>>>
>>>
>>> It did refer to the keys you used on your remote so it might not be
>>> too different for the next step.
>>
>> Yes, I've downloaded the correct service manual - but it seems to
>> assume that the OSD is working - which it ain't, apart from this
>> single line of text "Start Adjustment Menu"
>
> I tried a Google on the string, with quotes...
>
> This item is for a plasma set, so should not be used
> for an LCD exactly.
>
> http://www.controlcal.com/forum/showthread.php?t=1006
>
>    "
>     "Start Adjustment Menu" message will be displayed
>      followed by the Service Menu after few seconds.
>
>     You should see this as your display:
>
>     ADJUST {Picture Adjustment}
>     WB-ADJUST {White Balance Adjustment}
>     OPTION {Option Setting}
>     V-SUS {V-SUS Adjustment}
>     AGING
>     SRV-TOOL {Service Tool}
>     "1" & "2" buttons move through options
>    "
>
> That appears to be the entry point of the Service Menu.
> If a person was servicing the set (TV Repair), then
> they would attempt to get there. Your service menu
> is not rendering to screen.
>
> There is a second reference here. Last post.
>
> https://www.hifivision.com/threads/solution-to-find-out-panasonic-lcd-usage-hours.32728/
>
>
>    "You have to keep the {Channel -} button on the TV panel and
>     keep it pressed (do not release). While the above button is
>     pressed, press {INFO} button 3 times. <=== [Info button on Remote?]
>
>     At this point {Channel -} can be released."
>
>    [And press Exit to come out of Service Menu]
>
> Another example here, of a Service Menu.
>
> https://lcd-television-repair.com/newsletter/Panasonic_TV_Service_Menu.html
>
> So far, no suggestions for why the Service Menu won't paint.
>
>   Paul

No, sadly, I can't get anything other than the heading. I'm not sure how
useful it would be to know the total running time and number of starts.
Although it's 11 years old it hasn't been used very much. It was at my
holiday flat, which is occupied 25% of the time at the most. [I've now
got it back at my main home to try to fix it].
--
Cheers,
Roger

On 10/08/2021 15:51, Roger Mills wrote:
> No, sadly, I can't get anything other than the heading. I'm not sure how
> useful it would be to know the total running time and number of starts.
> Although it's 11 years old it hasn't been used very much. It was at my
> holiday flat, which is occupied 25% of the time at the most. [I've now
> got it back at my main home to try to fix it].

The service menu may also be where you calibrate the colour response of
the screen. So you don't really want to randomly mess with bits of it
you don't understand if you ever get it to appear.

--
Brian Gregory (in England).

On 10/08/2021 16:01, Brian Gregory wrote:
> On 10/08/2021 15:51, Roger Mills wrote:
>> No, sadly, I can't get anything other than the heading. I'm not sure
>> how useful it would be to know the total running time and number of
>> starts. Although it's 11 years old it hasn't been used very much. It
>> was at my holiday flat, which is occupied 25% of the time at the most.
>> [I've now got it back at my main home to try to fix it].
>
> The service menu may also be where you calibrate the colour response of
> the screen. So you don't really want to randomly mess with bits of it
> you don't understand if you ever get it to appear.
>

Agreed!
--
Cheers,
Roger

On 10/08/2021 15:45, Roger Mills wrote:
> On 10/08/2021 15:08, Theo wrote:
>> In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
>>> Indeed. But holding V- and pressing 0 (zero) on the remote 3 times
>>> *does* do something.
>>>
>>> It brings up a line of text on the screen saying "Start Adjustment Menu"
>>> - whatever that means. I can't then get it to do anything else but at
>>> least the screen can't be entirely dead.
>>
>> Service mode is operated through the number keys:
>>
>> Press the 3/4 button to change the adjustment values or function.
>> Press the 1/2 button to step up/down through the functions and
>> adjustments
>> Press the numerical button VOLUME (+/-) to change option item.
>> Press the OK button after each adjustment has been made to store the
>> required values.
>>
> That presupposes that some options are displayed - they aint!
>>
>>
>> Does this work:
>>
>> Self Check
>> Self-check is used to automatically check the bus lines and
>> hexadecimal code
>> of the TV set. To enter Self-Check mode, keep
>> pressing the down (-/v) button on the TV set and press the STATUS [i]
>> button on the remote control. To exit Self Check,
>> switch off the TV set at the power button.
>>
>>
> Ditto, can't get there either.
>
>> and you should check the power LED blinking sequence:
>>
>> Power LED blinking timing chart
>> 1. Subject
>> Information of LED Flashing timing chart.
>> 2. Contents
>> When abnormality has occurred the unit, the protection circuit
>> operates and
>> reset to the stand by mode.  At this time, the defective block can be
>> identified by number of blinking of the Power LED on the front panel
>> of the
>> unit.
>>
>> It flashes the LED N times, and then goes off, then N flashes, etc.  How
>> many flashes are there?  All point to the main board except where noted:
>>
>> 1=INVERTER_SOS (inverter board)
>> 2=FAN_SOS
>> 3=SOS
>> 4=SUB_F_12V
>> 5=MAIN9V
>> 6=SUB5V (remote receiver board)
>> 7=SUB3.3V
>> 8=MAIN3.3V
>> 9=SOUND_SOS
>> 10=EMERGENCY_SOS
>>
>> Theo
>>
>
> The light flashes continuously quite fast, with no pauses. I assume that
> means EMERGENCY_SOS - whatever that is!
>
> Incidentally, on P10 of the service manual there is a table of voltages
> to check on the A-board. Each one is referenced by a TP No. such as
> TP2765. But I can't see anything that obviously looks like test points,
> and most of the text on the board is too small to read. How do I find
> these points?

If you can find a model number of the board, you could try searching for
that along with "board view". There may be a PDF layout of the board, or
even a proper board view file designed to be loaded into board view
software.

Failing that, a big illuminated magnifier!

--
Cheers,

John.

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

In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
> On 10/08/2021 15:08, Theo wrote:
> The light flashes continuously quite fast, with no pauses. I assume that
> means EMERGENCY_SOS - whatever that is!

Not sure - EMERGENCY_SOS is down as 13 flashes (not 10) rather than a
continuous flash.

> Incidentally, on P10 of the service manual there is a table of voltages
> to check on the A-board. Each one is referenced by a TP No. such as
> TP2765. But I can't see anything that obviously looks like test points,
> and most of the text on the board is too small to read. How do I find
> these points?

You might have to trace them from the nearest IC that is labelled. For
example TP5405 (SUB5V) is from pin 3 of IC5405, which the Conductor Views
section shows labelled in quadrant 1D of the A-board.

Theo

Roger Mills <watt.tyler@gmail.com> wrote
> On 10/08/2021 15:08, Theo wrote:
>> In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
>>> Indeed. But holding V- and pressing 0 (zero) on the remote 3 times
>>> *does* do something.
>>>
>>> It brings up a line of text on the screen saying "Start Adjustment Menu"
>>> - whatever that means. I can't then get it to do anything else but at
>>> least the screen can't be entirely dead.
>>
>> Service mode is operated through the number keys:
>>
>> Press the 3/4 button to change the adjustment values or function.
>> Press the 1/2 button to step up/down through the functions and
>> adjustments
>> Press the numerical button VOLUME (+/-) to change option item.
>> Press the OK button after each adjustment has been made to store the
>> required values.
>>
> That presupposes that some options are displayed - they aint!
>>
>>
>> Does this work:
>>
>> Self Check
>> Self-check is used to automatically check the bus lines and hexadecimal
>> code
>> of the TV set. To enter Self-Check mode, keep
>> pressing the down (-/v) button on the TV set and press the STATUS [i]
>> button on the remote control. To exit Self Check,
>> switch off the TV set at the power button.
>>
>>
> Ditto, can't get there either.
>
>> and you should check the power LED blinking sequence:
>>
>> Power LED blinking timing chart
>> 1. Subject
>> Information of LED Flashing timing chart.
>> 2. Contents
>> When abnormality has occurred the unit, the protection circuit operates
>> and
>> reset to the stand by mode. At this time, the defective block can be
>> identified by number of blinking of the Power LED on the front panel of
>> the
>> unit.
>>
>> It flashes the LED N times, and then goes off, then N flashes, etc. How
>> many flashes are there? All point to the main board except where noted:
>>
>> 1=INVERTER_SOS (inverter board)
>> 2=FAN_SOS
>> 3=SOS
>> 4=SUB_F_12V
>> 5=MAIN9V
>> 6=SUB5V (remote receiver board)
>> 7=SUB3.3V
>> 8=MAIN3.3V
>> 9=SOUND_SOS
>> 10=EMERGENCY_SOS
>>
>> Theo
>>
>
> The light flashes continuously quite fast, with no pauses. I assume that
> means EMERGENCY_SOS - whatever that is!
>
> Incidentally, on P10 of the service manual there is a table of voltages to
> check on the A-board. Each one is referenced by a TP No. such as TP2765.
> But I can't see anything that obviously looks like test points, and most
> of the text on the board is too small to read. How do I find these points?

Take a photo of the board and blow it up.

On 10/08/2021 23:11, %% wrote:
> Roger Mills <watt.tyler@gmail.com> wrote
>> On 10/08/2021 15:08, Theo wrote:
>>> In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
>>>> Indeed. But holding V- and pressing 0 (zero) on the remote 3 times
>>>> *does* do something.
>>>>
>>>> It brings up a line of text on the screen saying "Start Adjustment
>>>> Menu"
>>>> - whatever that means. I can't then get it to do anything else but at
>>>> least the screen can't be entirely dead.
>>>
>>> Service mode is operated through the number keys:
>>>
>>> Press the 3/4 button to change the adjustment values or function.
>>> Press the 1/2 button to step up/down through the functions and
>>> adjustments
>>> Press the numerical button VOLUME (+/-) to change option item.
>>> Press the OK button after each adjustment has been made to store the
>>> required values.
>>>
>> That presupposes that some options are displayed - they aint!
>>>
>>>
>>> Does this work:
>>>
>>> Self Check
>>> Self-check is used to automatically check the bus lines and
>>> hexadecimal code
>>> of the TV set. To enter Self-Check mode, keep
>>> pressing the down (-/v) button on the TV set and press the STATUS [i]
>>> button on the remote control. To exit Self Check,
>>> switch off the TV set at the power button.
>>>
>>>
>> Ditto, can't get there either.
>>
>>> and you should check the power LED blinking sequence:
>>>
>>> Power LED blinking timing chart
>>> 1. Subject
>>> Information of LED Flashing timing chart.
>>> 2. Contents
>>> When abnormality has occurred the unit, the protection circuit
>>> operates and
>>> reset to the stand by mode.  At this time, the defective block can be
>>> identified by number of blinking of the Power LED on the front panel
>>> of the
>>> unit.
>>>
>>> It flashes the LED N times, and then goes off, then N flashes, etc.  How
>>> many flashes are there?  All point to the main board except where noted:
>>>
>>> 1=INVERTER_SOS (inverter board)
>>> 2=FAN_SOS
>>> 3=SOS
>>> 4=SUB_F_12V
>>> 5=MAIN9V
>>> 6=SUB5V (remote receiver board)
>>> 7=SUB3.3V
>>> 8=MAIN3.3V
>>> 9=SOUND_SOS
>>> 10=EMERGENCY_SOS
>>>
>>> Theo
>>>
>>
>> The light flashes continuously quite fast, with no pauses. I assume
>> that means EMERGENCY_SOS - whatever that is!
>>
>> Incidentally, on P10 of the service manual there is a table of
>> voltages to check on the A-board. Each one is referenced by a TP No.
>> such as TP2765. But I can't see anything that obviously looks like
>> test points, and most of the text on the board is too small to read.
>> How do I find these points?
>
> Take a photo of the board and blow it up.

That will certainly render it beyound all feasible repair........

In message <sevv7a$165i$2@gioia.aioe.org>, SH <i.love.spam@spam.com>
writes
>On 10/08/2021 23:11, %% wrote:
>> Take a photo of the board and blow it up.
>
>That will certainly render it beyound all feasible repair........

LOL!
--
John Hall "Hard work often pays off after time, but laziness always
pays off now." Anon

On 11/08/2021 08:45, SH wrote:
> On 10/08/2021 23:11, %% wrote:
>> Roger Mills <watt.tyler@gmail.com> wrote
>>> On 10/08/2021 15:08, Theo wrote:
>>>> In uk.d-i-y Roger Mills <watt.tyler@gmail.com> wrote:
>>>>> Indeed. But holding V- and pressing 0 (zero) on the remote 3 times
>>>>> *does* do something.
>>>>>
>>>>> It brings up a line of text on the screen saying "Start Adjustment
>>>>> Menu"
>>>>> - whatever that means. I can't then get it to do anything else but at
>>>>> least the screen can't be entirely dead.
>>>>
>>>> Service mode is operated through the number keys:
>>>>
>>>> Press the 3/4 button to change the adjustment values or function.
>>>> Press the 1/2 button to step up/down through the functions and
>>>> adjustments
>>>> Press the numerical button VOLUME (+/-) to change option item.
>>>> Press the OK button after each adjustment has been made to store the
>>>> required values.
>>>>
>>> That presupposes that some options are displayed - they aint!
>>>>
>>>>
>>>> Does this work:
>>>>
>>>> Self Check
>>>> Self-check is used to automatically check the bus lines and
>>>> hexadecimal code
>>>> of the TV set. To enter Self-Check mode, keep
>>>> pressing the down (-/v) button on the TV set and press the STATUS [i]
>>>> button on the remote control. To exit Self Check,
>>>> switch off the TV set at the power button.
>>>>
>>>>
>>> Ditto, can't get there either.
>>>
>>>> and you should check the power LED blinking sequence:
>>>>
>>>> Power LED blinking timing chart
>>>> 1. Subject
>>>> Information of LED Flashing timing chart.
>>>> 2. Contents
>>>> When abnormality has occurred the unit, the protection circuit
>>>> operates and
>>>> reset to the stand by mode.  At this time, the defective block can be
>>>> identified by number of blinking of the Power LED on the front panel
>>>> of the
>>>> unit.
>>>>
>>>> It flashes the LED N times, and then goes off, then N flashes, etc.
>>>> How
>>>> many flashes are there?  All point to the main board except where
>>>> noted:
>>>>
>>>> 1=INVERTER_SOS (inverter board)
>>>> 2=FAN_SOS
>>>> 3=SOS
>>>> 4=SUB_F_12V
>>>> 5=MAIN9V
>>>> 6=SUB5V (remote receiver board)
>>>> 7=SUB3.3V
>>>> 8=MAIN3.3V
>>>> 9=SOUND_SOS
>>>> 10=EMERGENCY_SOS
>>>>
>>>> Theo
>>>>
>>>
>>> The light flashes continuously quite fast, with no pauses. I assume
>>> that means EMERGENCY_SOS - whatever that is!
>>>
>>> Incidentally, on P10 of the service manual there is a table of
>>> voltages to check on the A-board. Each one is referenced by a TP No.
>>> such as TP2765. But I can't see anything that obviously looks like
>>> test points, and most of the text on the board is too small to read.
>>> How do I find these points?
>>
>> Take a photo of the board and blow it up.
>
> That will certainly render it beyond all feasible repair........

I've now found all but one of the testpoints (without any explosions!)
and will tabulate the results below. They're not marked on the board,
but they are shown on a schematic in the repair manual, so I was able to
reference them to specific pins of connectors.

Not sure how this will tabulate, but what I found was:

Description Expected Value Measured value
5VS 5.6v +/- 0.25v 5.72v
SUB_TNR_6V 5.6v +/- 0.25v 5.72v
GND 0 0.1mv
INVERTER_SOS 0 78mv
P17V 17v +/- 1v 18.35v
SUB_F_12V 12v +/- 1v 11.98v
INV_ON 2.85v +/- 2% 3.20v

The one I can't find is TV_SOS (which may possibly be the most
significant one). It only seems to be on a pin of IC5480, which is on
the *underside* of the board and not accessible with the board in place.

Any comments on these voltages?
--
Cheers,
Roger

On 11/08/2021 10:42, Roger Mills wrote:
> escription    Expected Value        Measured value
> 5VS        5.6v ± 0.25v        5.72v
> SUB_TNR_6V    5.6v ± 0.25v        5.72v
> GND        0            0.1mv
> INVERTER_SOS    0            78mv
> P17V        17v ± 1v        18.35v
> SUB_F_12V    12v ± 1v        11.98v
> INV_ON        2.85v ± 2%        3.20v
>
> The one I can't find is TV_SOS (which may possibly be the most
> significant one). It only seems to be on a pin of IC5480, which is on
> the *underside* of the board and not accessible with the board in place.
>
> Any comments on these voltages?

It looks to me like something isn't drawing any current when it should
be hence the high 17V. and the INV_ON is surely wrong.

One possible approach is to change every single electrolytic capacitor
in the vicinity of the power supply.

(I have memories as a trained electronic engineer of being highly
impressed as to how totally unskilled girls were repairing blown audio
power amplifiers. They removed *all* the power transistor and power
resistors and replaced them. These were placed in a bin and then tested
by a technician on a transistor tester - good ones went back to the
repair line as spares. Any boards that didn't work were placed in a box
for the technician to diagnose)

--
I would rather have questions that cannot be answered...
....than to have answers that cannot be questioned

Richard Feynman