Every so often, with live TV on my LG 43" 15 year old LCD TV, half the screen
becomes garbled. Pic here:

https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP

Changing the channel, or other sources like DVD seem OK. I can only think this
is an aerial problem. It's in the attic, but signal meaures 90%, with 100%
quality across all channels, according to the TV's settings display.

Could this be the aerial, or something else? How best to test the aerial?

--
Cheers, Rob, Sheffield UK

RJH wrote:

> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP

faulty RAM?
faulty ribbon connector to display panel?

> Changing the channel, or other sources like DVD seem OK. I can only think this
> is an aerial problem.

I don't see how an aerial could cause that.

On 20/11/2022 10:17, RJH wrote:
> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the screen
> becomes garbled. Pic here:
>
> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP

I think the TV is gagging on Victoria's impressive mammaries :-)

>
> Changing the channel, or other sources like DVD seem OK. I can only think this
> is an aerial problem. It's in the attic, but signal meaures 90%, with 100%
> quality across all channels, according to the TV's settings display.
>
> Could this be the aerial, or something else? How best to test the aerial?
>
TBH, joking apart, RF interference/ low signal wouldn't be just part of
the screen.
I suspect there is a hardware fault in the TV

--
“Some people like to travel by train because it combines the slowness of
a car with the cramped public exposure of 
an airplane.”

Dennis Miller

On 20/11/2022 10:17, RJH wrote:
> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the screen
> becomes garbled. Pic here:
>
> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>
> Changing the channel, or other sources like DVD seem OK. I can only think this
> is an aerial problem. It's in the attic, but signal meaures 90%, with 100%
> quality across all channels, according to the TV's settings display.
>
> Could this be the aerial, or something else? How best to test the aerial?

That does not look like a typical aerial signal issue - more likely a TV
fault - dodgy TCon board, or perhaps a poor flex connection to the screen.

--
Cheers,

John.

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

On the other hand, if no other sources are implicated, then it can hardly be
display related either. It sounds like its in the part of the set that
processes the signals from off air to the place where the source switching
occurs

Have you found a pattern in which channels are affected? I mean, have a
check to see which channels are on each multiplex and see if it aligns with
when it happens.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Andy Burns" <usenet@andyburns.uk> wrote in message
news:jtudg7F5f6eU1@mid.individual.net...
> RJH wrote:
>
>> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>
> faulty RAM?
> faulty ribbon connector to display panel?
>
>> Changing the channel, or other sources like DVD seem OK. I can only think
>> this
>> is an aerial problem.
>
> I don't see how an aerial could cause that.

On 20/11/2022 12:44, John Rumm wrote:
> On 20/11/2022 10:17, RJH wrote:
>> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the
>> screen
>> becomes garbled. Pic here:
>>
>> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>>
>> Changing the channel, or other sources like DVD seem OK. I can only
>> think this
>> is an aerial problem. It's in the attic, but signal meaures 90%, with
>> 100%
>> quality across all channels, according to the TV's settings display.
>>
>> Could this be the aerial, or something else? How best to test the aerial?
>
> That does not look like a typical aerial signal issue - more likely a TV
> fault - dodgy TCon board, or perhaps a poor flex connection to the screen.

My though. My only question was this intermittent, worse in cold or hot.
Is it temporarily resolved with a good old fashioned tap to the case?

RJH <patchmoney@gmx.com> wrote:
> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the screen
> becomes garbled. Pic here:
>
> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>
> Changing the channel, or other sources like DVD seem OK. I can only think this
> is an aerial problem. It's in the attic, but signal meaures 90%, with 100%
> quality across all channels, according to the TV's settings display.
>
> Could this be the aerial, or something else? How best to test the aerial?
>

If it is only live TV, I’d check the antenna and coax first. Has a tree
grown in the path? Could the antenna have been moved? Coax damaged? Is the
plug connection good?

Those are ‘easy’ things (almost) any DIYer can check.

(I’d not rely too much on the signal measurements due the problem being
intermittent. )

Don’t assume the coax can’t be damaged just because it is in the loft.
Years ago, we had a squirrel chew a coax in our loft.

In article <tlcus8$3gc3h$1@dont-email.me>,
RJH <patchmoney@gmx.com> wrote:
> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the screen
> becomes garbled. Pic here:

> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP

> Changing the channel, or other sources like DVD seem OK. I can only think this
> is an aerial problem. It's in the attic, but signal meaures 90%, with 100%
> quality across all channels, according to the TV's settings display.

> Could this be the aerial, or something else? How best to test the aerial?

Don't think that's RF problems.

Have you Googled using the set make and model and this fault? In general,
few faults are unique to just one example. If common, you may even find a
repairer for this exact fault on Ebay.

--
*(over a sketch of the titanic) "The boat sank - get over it

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

On 20/11/2022 10:17, RJH wrote:
> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the screen
> becomes garbled. Pic here:
>
> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>
> Changing the channel, or other sources like DVD seem OK. I can only think this
> is an aerial problem. It's in the attic, but signal meaures 90%, with 100%
> quality across all channels, according to the TV's settings display.

Signal really needs to be 100%. We only see problems when there is
extremely heavy rain and on the borderline signal channels.
>
> Could this be the aerial, or something else? How best to test the aerial?

It is a low signal failure where the MPEG stream has a bad block that
passes the CRC and results in insane decoding. It typically flings the
image sideways and turns the picture into psychedelic colours or pastel.

It should correct itself when the next iframe comes along but talking
heads are very prone to being screwed up for extended periods. There is
a similar low signal fault where the iframe itself is corrupted and
repaints only part of the screen leaving a hybrid of two scenes.

--
Regards,
Martin Brown

On 20/11/2022 11:28, The Natural Philosopher wrote:
> On 20/11/2022 10:17, RJH wrote:
>> Every so often, with live TV on my LG 43" 15 year old LCD TV, half the
>> screen
>> becomes garbled. Pic here:
>>
>> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>
> I think the TV is gagging on Victoria's impressive mammaries :-)
>
>>
>> Changing the channel, or other sources like DVD seem OK. I can only
>> think this
>> is an aerial problem. It's in the attic, but signal meaures 90%, with
>> 100%
>> quality across all channels, according to the TV's settings display.
>>
>> Could this be the aerial, or something else? How best to test the aerial?
>>
> TBH, joking apart, RF interference/ low signal wouldn't be just part of
> the screen.
> I suspect there is a hardware fault in the TV

Yes it will. The MPEG stream is corrupt. The image up to the point where
decoding failed is fine and the parts after it have wrong colours and
some random positional shift relative to the rest of the image. Once a
bad block has been interpreted the image decoding presses on regardless
doing its best to make sense of what is by then a random bitstream.

The fault will persist until the next iframe comes along to repaint the
entire screen.

--
Regards,
Martin Brown

Martin Brown wrote:

> The Natural Philosopher wrote:
>
>> RF interference/ low signal wouldn't be just part of the screen.
>
> Yes it will. The MPEG stream is corrupt. The image up to the point where
> decoding failed is fine and the parts after it have wrong colours and some
> random positional shift relative to the rest of the image. Once a bad block has
> been interpreted the image decoding presses on regardless doing its best to make
> sense of what is by then a random bitstream.
>
> The fault will persist until the next iframe comes along to repaint the entire
> screen.

We haven't had sufficient description of the fault from the owner to know what's
happening, if it occasionally glitches like that, it could be corrupt p-frames
"mangling" the output, normally it looks a lot more random than that with
corruopt streams though, but as you say, it would all reset again at the next
i-frame.

But if it stays with that "cut in quarters" appearance for more than a couple of
seconds, I'd say it's faulty hardware or connections inside the TV.

On 21/11/2022 10:41, Andy Burns wrote:
>
> Martin Brown wrote:
>
>> The Natural Philosopher wrote:
>>
>>> RF interference/ low signal wouldn't be just part of the screen.
>>
>> Yes it will. The MPEG stream is corrupt. The image up to the point
>> where decoding failed is fine and the parts after it have wrong
>> colours and some random positional shift relative to the rest of the
>> image. Once a bad block has been interpreted the image decoding
>> presses on regardless doing its best to make sense of what is by then
>> a random bitstream.
>>
>> The fault will persist until the next iframe comes along to repaint
>> the entire screen.
>
> We haven't had sufficient description of the fault from the owner to
> know what's happening, if it occasionally glitches like that, it could
> be corrupt p-frames "mangling" the output, normally it looks a lot more
> random than that with corruopt streams though, but as you say, it would
> all reset again at the next i-frame.
>
> But if it stays with that "cut in quarters" appearance for more than a
> couple of seconds, I'd say it's faulty hardware or connections inside
> the TV.

The way to tell would be to have a close up of the pixels at the
transition between good picture and bad. Armed with that pixel level
info I can quickly determine if it is an MPEG decoding error. Resolution
at full frame isn't up to seeing that level of detail.

The damage will show as one 16x16 block where an 8x8 sub-block is only
partially right and then the next block right or down is some crazy
colour. It invariably throws the picture sideways by a random shift.

If the fail always occurs in the same place then I'd agree it is most
likely hardware memory fault but I have seen quite few variants of the
same thing on marginal satellite TV during extreme thunderstorms with
thick cloud preventing an adequate signal from reaching the decoder.

The failure is suspiciously close to half way across the screen so
either interpretation is possible at the moment.

The more common decoding failure mode is a few blocks go haywire and the
decoder bales out leaving correctly coloured cubist artefacts and maybe
the odd ultrasonic click or gap on the sound track.

--
Regards,
Martin Brown

In article <ju12u4FhtugU1@mid.individual.net>, Andy Burns
<usenet@andyburns.uk> wrote:

> Martin Brown wrote:

> > The Natural Philosopher wrote:
> >
> >> RF interference/ low signal wouldn't be just part of the screen.
> >
> > Yes it will. The MPEG stream is corrupt. The image up to the point
> > where decoding failed is fine and the parts after it have wrong
> > colours and some random positional shift relative to the rest of the
> > image. Once a bad block has been interpreted the image decoding
> > presses on regardless doing its best to make sense of what is by then
> > a random bitstream.
> >
> > The fault will persist until the next iframe comes along to repaint the
> > entire screen.

> We haven't had sufficient description of the fault from the owner to know
> what's happening, if it occasionally glitches like that, it could be
> corrupt p-frames "mangling" the output, normally it looks a lot more
> random than that with corruopt streams though, but as you say, it would
> all reset again at the next i-frame.

> But if it stays with that "cut in quarters" appearance for more than a
> couple of seconds, I'd say it's faulty hardware or connections inside
> the TV.

I had a fault looking very similar on a computer monitor. No MPEG involved

--
from KT24 in Surrey, England - sent from my RISC OS 4té
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 21/11/2022 12:22, charles wrote:
> In article <ju12u4FhtugU1@mid.individual.net>, Andy Burns
> <usenet@andyburns.uk> wrote:
>
>> Martin Brown wrote:
>
>>> The Natural Philosopher wrote:
>>>
>>>> RF interference/ low signal wouldn't be just part of the screen.
>>>
>>> Yes it will. The MPEG stream is corrupt. The image up to the point
>>> where decoding failed is fine and the parts after it have wrong
>>> colours and some random positional shift relative to the rest of the
>>> image. Once a bad block has been interpreted the image decoding
>>> presses on regardless doing its best to make sense of what is by then
>>> a random bitstream.
>>>
>>> The fault will persist until the next iframe comes along to repaint the
>>> entire screen.
>
>> We haven't had sufficient description of the fault from the owner to know
>> what's happening, if it occasionally glitches like that, it could be
>> corrupt p-frames "mangling" the output, normally it looks a lot more
>> random than that with corruopt streams though, but as you say, it would
>> all reset again at the next i-frame.
>
>> But if it stays with that "cut in quarters" appearance for more than a
>> couple of seconds, I'd say it's faulty hardware or connections inside
>> the TV.
>
> I had a fault looking very similar on a computer monitor. No MPEG involved

I'm not saying it is definitely a decoding fault, but that is pretty
much what an MPEG decoding fault looks like. The sideways throw and
colour shift can vary enormously when this happens.

A hardware fault in the memory addressing is also possible. Made much
more likely if it always occurs in the same place on the screen.

--
Regards,
Martin Brown

On 20/11/2022 19:10, Martin Brown wrote:
> On 20/11/2022 10:17, RJH wrote:
>> Every so often, with live TV on my LG 43" 15 year old LCD TV, half
>> the screen
>> becomes garbled. Pic here:
>>
>> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>>
That is not a reception or tuner problem. DVB coding uses interleaved
data, you cannot get errors segregated in that way across a image

On 21 Nov 2022 at 13:35:18 GMT, Martin Brown wrote:

> On 21/11/2022 12:22, charles wrote:
>> In article <ju12u4FhtugU1@mid.individual.net>, Andy Burns
>> <usenet@andyburns.uk> wrote:
>>
>>> Martin Brown wrote:
>>
>>>> The Natural Philosopher wrote:
>>>>
>>>>> RF interference/ low signal wouldn't be just part of the screen.
>>>>
>>>> Yes it will. The MPEG stream is corrupt. The image up to the point
>>>> where decoding failed is fine and the parts after it have wrong
>>>> colours and some random positional shift relative to the rest of the
>>>> image. Once a bad block has been interpreted the image decoding
>>>> presses on regardless doing its best to make sense of what is by then
>>>> a random bitstream.
>>>>
>>>> The fault will persist until the next iframe comes along to repaint the
>>>> entire screen.
>>
>>> We haven't had sufficient description of the fault from the owner to know
>>> what's happening, if it occasionally glitches like that, it could be
>>> corrupt p-frames "mangling" the output, normally it looks a lot more
>>> random than that with corruopt streams though, but as you say, it would
>>> all reset again at the next i-frame.
>>

I haven't left it in that stae for too long - maybe a minute or two. As I say,
changing channel solves it.

>>> But if it stays with that "cut in quarters" appearance for more than a
>>> couple of seconds, I'd say it's faulty hardware or connections inside
>>> the TV.
>>
>> I had a fault looking very similar on a computer monitor. No MPEG involved
>
> I'm not saying it is definitely a decoding fault, but that is pretty
> much what an MPEG decoding fault looks like. The sideways throw and
> colour shift can vary enormously when this happens.
>
> A hardware fault in the memory addressing is also possible. Made much
> more likely if it always occurs in the same place on the screen.

I'll make a note of the citrcumstances next time. And have a look at the
aerial/cables. For now, though, it's not much more than a minor inconvenience.

Thanks for all the pointers.

--
Cheers, Rob, Sheffield UK

On 21/11/2022 14:32, Mark Carver wrote:
> On 20/11/2022 19:10, Martin Brown wrote:
>> On 20/11/2022 10:17, RJH wrote:
>>> Every so often, with live TV on my LG 43" 15 year old LCD TV, half
>>> the screen
>>> becomes garbled. Pic here:
>>>
>>> https://www.icloud.com/sharedalbum/#B0zGlxzuqGXFmRP
>>>
> That is not a reception or tuner problem. DVB coding uses interleaved
> data, you cannot get errors segregated in that way across a image

<panto mode>Oh yes you can!</panto mode>

I grant you that it is rare and requires the signal to be very close to
dropping out entirely but a TV on a digital stream can be provoked to do
exactly that and a couple of other weird variants if the MPEG stream for
a key frame is incorrect after the decoder has finished with it.

Usually you get 16x16 blocks that are wrong but sometimes it will do
almost exactly that linear shift and wild crazy colour change.

It could still be a memory fault though.

If it always occurs in the same place then it *is* a memory fault or a
defective connector on the display itself. If changing channel fixes it
or it only ever appears on one channel then it is a firmware bug in the
decoder (there are plenty of those too). Unplayable media content.

Several older sets have some of the p frame coefficients in the wrong
way around. If you look very closely when the news is on and they pan
across a table with a shallow diagonal line it breaks into a small sawtooth.

Running people also shed more bit error smoke in the sky than they ought
to. Those are the only symptoms of that particular bug.

--
Regards,
Martin Brown

On 21/11/2022 18:05, RJH wrote:
> I'll make a note of the citrcumstances next time. And have a look at the
> aerial/cables. For now, though, it's not much more than a minor inconvenience.

Its not RF based. Its a hardware fault.

--
"I guess a rattlesnake ain't risponsible fer bein' a rattlesnake, but ah
puts mah heel on um jess the same if'n I catches him around mah chillun".

On 21/11/2022 18:05, RJH wrote:
> On 21 Nov 2022 at 13:35:18 GMT, Martin Brown wrote:
>
>> On 21/11/2022 12:22, charles wrote:
>>> In article <ju12u4FhtugU1@mid.individual.net>, Andy Burns
>>> <usenet@andyburns.uk> wrote:
>>>
>>>> Martin Brown wrote:
>>>
>>>>> The Natural Philosopher wrote:
>>>>>
>>>>>> RF interference/ low signal wouldn't be just part of the screen.
>>>>>
>>>>> Yes it will. The MPEG stream is corrupt. The image up to the point
>>>>> where decoding failed is fine and the parts after it have wrong
>>>>> colours and some random positional shift relative to the rest of the
>>>>> image. Once a bad block has been interpreted the image decoding
>>>>> presses on regardless doing its best to make sense of what is by then
>>>>> a random bitstream.
>>>>>
>>>>> The fault will persist until the next iframe comes along to repaint the
>>>>> entire screen.
>>>
>>>> We haven't had sufficient description of the fault from the owner to know
>>>> what's happening, if it occasionally glitches like that, it could be
>>>> corrupt p-frames "mangling" the output, normally it looks a lot more
>>>> random than that with corruopt streams though, but as you say, it would
>>>> all reset again at the next i-frame.
>>>
>
> I haven't left it in that stae for too long - maybe a minute or two. As I say,
> changing channel solves it.
>
>>>> But if it stays with that "cut in quarters" appearance for more than a
>>>> couple of seconds, I'd say it's faulty hardware or connections inside
>>>> the TV.
>>>
>>> I had a fault looking very similar on a computer monitor. No MPEG involved
>>
>> I'm not saying it is definitely a decoding fault, but that is pretty
>> much what an MPEG decoding fault looks like. The sideways throw and
>> colour shift can vary enormously when this happens.
>>
>> A hardware fault in the memory addressing is also possible. Made much
>> more likely if it always occurs in the same place on the screen.
>
> I'll make a note of the citrcumstances next time. And have a look at the
> aerial/cables. For now, though, it's not much more than a minor inconvenience.

I might have hoped by now you would have dismissed areas such as the
aerial and cables from being the cause!

> Thanks for all the pointers.
>

On 22 Nov 2022 at 11:26:50 GMT, Fredxx wrote:

> On 21/11/2022 18:05, RJH wrote:
>> On 21 Nov 2022 at 13:35:18 GMT, Martin Brown wrote:
>>
>>> On 21/11/2022 12:22, charles wrote:
>>>> In article <ju12u4FhtugU1@mid.individual.net>, Andy Burns
>>>> <usenet@andyburns.uk> wrote:
>>>>
>>>>> Martin Brown wrote:
>>>>
>>>>>> The Natural Philosopher wrote:
>>>>>>
>>>>>>> RF interference/ low signal wouldn't be just part of the screen.
>>>>>>
>>>>>> Yes it will. The MPEG stream is corrupt. The image up to the point
>>>>>> where decoding failed is fine and the parts after it have wrong
>>>>>> colours and some random positional shift relative to the rest of the
>>>>>> image. Once a bad block has been interpreted the image decoding
>>>>>> presses on regardless doing its best to make sense of what is by then
>>>>>> a random bitstream.
>>>>>>
>>>>>> The fault will persist until the next iframe comes along to repaint the
>>>>>> entire screen.
>>>>
>>>>> We haven't had sufficient description of the fault from the owner to know
>>>>> what's happening, if it occasionally glitches like that, it could be
>>>>> corrupt p-frames "mangling" the output, normally it looks a lot more
>>>>> random than that with corruopt streams though, but as you say, it would
>>>>> all reset again at the next i-frame.
>>>>
>>
>> I haven't left it in that stae for too long - maybe a minute or two. As I say,
>> changing channel solves it.
>>
>>>>> But if it stays with that "cut in quarters" appearance for more than a
>>>>> couple of seconds, I'd say it's faulty hardware or connections inside
>>>>> the TV.
>>>>
>>>> I had a fault looking very similar on a computer monitor. No MPEG involved
>>>
>>> I'm not saying it is definitely a decoding fault, but that is pretty
>>> much what an MPEG decoding fault looks like. The sideways throw and
>>> colour shift can vary enormously when this happens.
>>>
>>> A hardware fault in the memory addressing is also possible. Made much
>>> more likely if it always occurs in the same place on the screen.
>>
>> I'll make a note of the citrcumstances next time. And have a look at the
>> aerial/cables. For now, though, it's not much more than a minor inconvenience.
>
> I might have hoped by now you would have dismissed areas such as the
> aerial and cables from being the cause!

Yes yes, but Martin Brown seems to be making a comprehensive case for a
possible aerial issue.

--
Cheers, Rob, Sheffield UK

RJH wrote:

> Fredxx wrote:
>
>> I might have hoped by now you would have dismissed areas such as the
>> aerial and cables from being the cause!
>
> Yes yes, but Martin Brown seems to be making a comprehensive case for a
> possible aerial issue.

He's the only one who is though; if it was an RF side issue, I would not expect
anything like such a "sharp" area of corruption, on the other hand I wouldn't
expect just random mush, but I would expect a *lot* less order within the
displayed picture.

On 22/11/2022 16:41, Andy Burns wrote:
> RJH wrote:
>
>> Fredxx wrote:
>>
>>> I might have hoped by now you would have dismissed areas such as the
>>> aerial and cables from being the cause!
>>
>> Yes yes, but Martin Brown seems to be making a comprehensive case for a
>> possible aerial issue.
>
> He's the only one who is though;  if it was an RF side issue, I would
> not expect anything like such a "sharp" area of corruption, on the
> other hand I wouldn't expect just random mush, but I would expect a
> *lot* less order within the displayed picture.
>
>
+1

On 22/11/2022 16:34, RJH wrote:
> On 22 Nov 2022 at 11:26:50 GMT, Fredxx wrote:
>
>> On 21/11/2022 18:05, RJH wrote:
>>> On 21 Nov 2022 at 13:35:18 GMT, Martin Brown wrote:
>>>
>>>> On 21/11/2022 12:22, charles wrote:
>>>>> In article <ju12u4FhtugU1@mid.individual.net>, Andy Burns
>>>>> <usenet@andyburns.uk> wrote:
>>>>>
>>>>>> Martin Brown wrote:
>>>>>
>>>>>>> The Natural Philosopher wrote:
>>>>>>>
>>>>>>>> RF interference/ low signal wouldn't be just part of the screen.
>>>>>>>
>>>>>>> Yes it will. The MPEG stream is corrupt. The image up to the point
>>>>>>> where decoding failed is fine and the parts after it have wrong
>>>>>>> colours and some random positional shift relative to the rest of the
>>>>>>> image. Once a bad block has been interpreted the image decoding
>>>>>>> presses on regardless doing its best to make sense of what is by then
>>>>>>> a random bitstream.
>>>>>>>
>>>>>>> The fault will persist until the next iframe comes along to repaint the
>>>>>>> entire screen.
>>>>>
>>>>>> We haven't had sufficient description of the fault from the owner to know
>>>>>> what's happening, if it occasionally glitches like that, it could be
>>>>>> corrupt p-frames "mangling" the output, normally it looks a lot more
>>>>>> random than that with corruopt streams though, but as you say, it would
>>>>>> all reset again at the next i-frame.
>>>>>
>>>
>>> I haven't left it in that stae for too long - maybe a minute or two. As I say,
>>> changing channel solves it.
>>>
>>>>>> But if it stays with that "cut in quarters" appearance for more than a
>>>>>> couple of seconds, I'd say it's faulty hardware or connections inside
>>>>>> the TV.
>>>>>
>>>>> I had a fault looking very similar on a computer monitor. No MPEG involved
>>>>
>>>> I'm not saying it is definitely a decoding fault, but that is pretty
>>>> much what an MPEG decoding fault looks like. The sideways throw and
>>>> colour shift can vary enormously when this happens.
>>>>
>>>> A hardware fault in the memory addressing is also possible. Made much
>>>> more likely if it always occurs in the same place on the screen.
>>>
>>> I'll make a note of the citrcumstances next time. And have a look at the
>>> aerial/cables. For now, though, it's not much more than a minor inconvenience.
>>
>> I might have hoped by now you would have dismissed areas such as the
>> aerial and cables from being the cause!
>
> Yes yes, but Martin Brown seems to be making a comprehensive case for a
> possible aerial issue.
>
I don't know why. Anyone who has operated a digital TV with a bad
signal knows that isn't what happens. Anyone who has operated a PC with
a bad graphics card or monitor knows that that is exactly what happens
I'd hazard a guess at bad RAM that gets used but not all the time.

--
"Women actually are capable of being far more than the feminists will
let them."

On 22/11/2022 17:09, Mark Carver wrote:
> On 22/11/2022 16:41, Andy Burns wrote:
>> RJH wrote:
>>
>>> Fredxx wrote:
>>>
>>>> I might have hoped by now you would have dismissed areas such as the
>>>> aerial and cables from being the cause!
>>>
>>> Yes yes, but Martin Brown seems to be making a comprehensive case for a
>>> possible aerial issue.
>>
>> He's the only one who is though;  if it was an RF side issue, I would
>> not expect anything like such a "sharp" area of corruption, on the
>> other hand I wouldn't expect just random mush, but I would expect a
>> *lot* less order within the displayed picture.
>>
>>
> +1
+2

--
"Women actually are capable of being far more than the feminists will
let them."

On 22 Nov 2022 at 18:14:23 GMT, The Natural Philosopher wrote:

> On 22/11/2022 17:09, Mark Carver wrote:
>> On 22/11/2022 16:41, Andy Burns wrote:
>>> RJH wrote:
>>>
>>>> Fredxx wrote:
>>>>
>>>>> I might have hoped by now you would have dismissed areas such as the
>>>>> aerial and cables from being the cause!
>>>>
>>>> Yes yes, but Martin Brown seems to be making a comprehensive case for a
>>>> possible aerial issue.
>>>
>>> He's the only one who is though; if it was an RF side issue, I would
>>> not expect anything like such a "sharp" area of corruption, on the
>>> other hand I wouldn't expect just random mush, but I would expect a
>>> *lot* less order within the displayed picture.
>>>
>>>
>> +1
> +2

OK thanks!
--
Cheers, Rob, Sheffield UK