Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Sony CRT TV not switching on

I have got a Sony Wega Flat CRT TV €“ KV-AR21M83. One day its picture gone bad. Before this it never gave problem. Its picture started to give disturbance, coloration problem, colour bleeding and also sometimes gave noise. So, I stopped using the TV but occasionally I switched it on to see its situation. I called a technician from Sony but he told that he does not know that where the fault is and Ill have to take it to service centre but I did not take it. One day I again switched it on but suddenly the disturbance increased. So I got frightened and turned it off. When I again switched it on the TV started to operate normally. But another problem came up. Whenever I switched on the TV and before the picture came on the screen, the TV displayed a green colour glow and also green coloured horizontal lines on the screen appeared for about 2 seconds and then vanished. The lines were not completely perpendicular. The lines were somewhat slanting, raised from the right side. The picture itself was fine but maybe with somewhat reduced colour accuracy. I felt it so. I could be wrong. Anyways, I used the TV for 1 - 2 months and then closed and covered it as I was using another TV.

After few months, I needed to use this TV again. So I switched it on. But the TV did not switch on. This was very much unexpected. Only the LED light on the TV blinks 8 times in red. I searched to see that do these blinks indicate something. I found out that 8 blinks as in my case indicates problem with audio IC IC406. But there was no audio problem in this TV. Only picture had issues.

So, what exactly has gone wrong in the TV? Is it the same component which is responsible for TV not switching on and the earlier picture problems?

I hope that nothing has happened to the picture tube as it is not replaceable. But If the fault does exist in some component of the picture tube then is that component replaceable / repairable or not?

Please Help. I am a novice.
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Default Sony CRT TV not switching on

In Sonys of that vintage they has alot of problems wit the CRTs. Usually the green for some reason. The gun gets weak and then shorts sometimes.

The AKB keeps the greyscale right until the green gun is too weak to do so. Then it is overdriven. This happens sometimes without notice.

The codes are not all that good. IF the main power supply is blown and it sees no voltage at the supply to the audio IC and thinks it is shorted. Like some cars, you read the codes ad they do not tell the whole story. You have to look over all the codes it actually has. In the US they standardised it, but not on TVs. But before that you had to interpret them by the model. And ironically if you got a code (even today) that says too lean alot of people think fuel filter or dirty injectors, but it really needs an O2 (lambda) sensor and is actually running too rich.

You actually could have a bad audio IC, you said it made a noise. But with the green on the screen with the (retrace) lines I suspect the CRT very greatly. The audio IC has nothing to do with the color.

If you really like CRT TVs, find a Toshiba somewhere. If the CRT is good after all these years it will probably be good for quite some time. Actually if you find a Sony from the 1980s that still looks good it might last a while.
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Default Sony CRT TV not switching on

On Fri, 15 Jul 2016 10:44:17 -0700 (PDT),
wrote:

I have got a Sony Wega Flat CRT TV – KV-AR21M83. One day its picture gone bad. Before this it never gave problem. Its picture started to give disturbance, coloration problem, colour bleeding and also sometimes gave noise. So, I stopped using the TV but occasionally I switched it on to see its situation. I called a technician from Sony but he told that he does not know that where the fault is and I’ll have to take it to service centre but I did not take it. One day I again switched it on but suddenly the disturbance increased. So I got frightened and turned it off. When I again switched it on the TV started to operate normally. But another problem came up. Whenever I switched on the TV and before the picture came on the screen, the TV displayed a green colour glow and also green coloured horizontal lines on the screen appeared for about 2 seconds and then vanished. The lines were not completely perpendicular. The lines were somewhat slanting, raised from the right side. The picture


I presume those are raster return lines, that would be blanked out if
things were working normally. The electron beam goes from one side
to the other illuminating the screen, but then it has to get back to
the first side without adding unwanted light to the picture. I
never did understand why the slope was more than two lines hight at
the high end, however.

itself was fine but maybe with somewhat reduced colour accuracy. I felt it so. I could be wrong. Anyways, I used the TV for 1 - 2 months and then closed and covered it as I was using another TV.

After few months, I needed to use this TV again. So I switched it on. But the TV did not switch on. This was very much unexpected. Only the LED light on the TV blinks 8 times in red. I searched to see that do these blinks indicate something. I found out that 8 blinks as in my case indicates problem with audio IC IC406. But there was no audio problem in this TV. Only picture had issues.

So, what exactly has gone wrong in the TV?


Hold the TV closer to your computer so I can figure that out.

Is it the same component which is responsible for TV not switching on and the earlier picture problems?


Maybe.

I hope that nothing has happened to the picture tube as it is not replaceable.


When there is no picture, most of the people I dealt with assumed the
problem was the picture tube, and it never was. Old bad picture
tubes on black and white TVs have a silvery appearance, but I don't
know how to describe the same problem on color tvs. But it's not what
you've described.

But If the fault does exist in some component of the picture tube then is that component replaceable / repairable or not?

Please Help. I am a novice.

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Default Sony CRT TV not switching on

On Saturday, July 16, 2016 at 7:25:43 AM UTC-4, Bruce Esquibel wrote:

The only money I'd put into it is paying someone to haul it away.

-bruce


And that's no longer simple. The trash pickup won't take it, and it now costs $25 per unit in my area to dispose of.



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On Saturday, July 16, 2016 at 6:12:56 AM UTC+5:30, wrote:
In Sonys of that vintage they has alot of problems wit the CRTs. Usually the green for some reason. The gun gets weak and then shorts sometimes.

The AKB keeps the greyscale right until the green gun is too weak to do so. Then it is overdriven. This happens sometimes without notice.


Thanks but what is AKB?

The codes are not all that good. IF the main power supply is blown and it sees no voltage at the supply to the audio IC and thinks it is shorted. Like some cars, you read the codes ad they do not tell the whole story. You have to look over all the codes it actually has. In the US they standardised it, but not on TVs. But before that you had to interpret them by the model.. And ironically if you got a code (even today) that says too lean alot of people think fuel filter or dirty injectors, but it really needs an O2 (lambda) sensor and is actually running too rich.

You actually could have a bad audio IC, you said it made a noise. But with the green on the screen with the (retrace) lines I suspect the CRT very greatly. The audio IC has nothing to do with the color.



Maybe but that noise was due to picture disturbance. Yes, I think these codes do not always give the correct indication of fault or these codes have got even more meaning which is not given in the code paper.


If you really like CRT TVs, find a Toshiba somewhere. If the CRT is good after all these years it will probably be good for quite some time. Actually if you find a Sony from the 1980s that still looks good it might last a while.


Is Toshiba still manufacturing CRT TV?
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Default Sony CRT TV not switching on

On Sunday, July 17, 2016 at 12:40:01 AM UTC+5:30, Micky wrote:
On Fri, 15 Jul 2016 10:44:17 -0700 (PDT), Ronald wrote:

I have got a Sony Wega Flat CRT TV €“ KV-AR21M83. One day its picture gone bad. Before this it never gave problem. Its picture started to give disturbance, coloration problem, colour bleeding and also sometimes gave noise. So, I stopped using the TV but occasionally I switched it on to see its situation. I called a technician from Sony but he told that he does not know that where the fault is and Ill have to take it to service centre but I did not take it. One day I again switched it on but suddenly the disturbance increased. So I got frightened and turned it off. When I again switched it on the TV started to operate normally. But another problem came up. Whenever I switched on the TV and before the picture came on the screen, the TV displayed a green colour glow and also green coloured horizontal lines on the screen appeared for about 2 seconds and then vanished. The lines were not completely perpendicular. The lines were somewhat slanting, raised from the right side. The picture


I presume those are raster return lines, that would be blanked out if
things were working normally. The electron beam goes from one side
to the other illuminating the screen, but then it has to get back to
the first side without adding unwanted light to the picture. I
never did understand why the slope was more than two lines hight at
the high end, however.


Yes, it seems raster line. I have heard about them but don't understand them well. It looked like some filament in picture tube is glowing in green colour.

itself was fine but maybe with somewhat reduced colour accuracy. I felt it so. I could be wrong. Anyways, I used the TV for 1 - 2 months and then closed and covered it as I was using another TV.

After few months, I needed to use this TV again. So I switched it on. But the TV did not switch on. This was very much unexpected. Only the LED light on the TV blinks 8 times in red. I searched to see that do these blinks indicate something. I found out that 8 blinks as in my case indicates problem with audio IC IC406. But there was no audio problem in this TV. Only picture had issues.

So, what exactly has gone wrong in the TV?


Hold the TV closer to your computer so I can figure that out.

Is it the same component which is responsible for TV not switching on and the earlier picture problems?


Maybe.

I hope that nothing has happened to the picture tube as it is not replaceable.


When there is no picture, most of the people I dealt with assumed the
problem was the picture tube, and it never was. Old bad picture
tubes on black and white TVs have a silvery appearance, but I don't
know how to describe the same problem on color tvs. But it's not what
you've described.



Yes, most likely the problem is not in the picture tube.


But If the fault does exist in some component of the picture tube then is that component replaceable / repairable or not?

Please Help. I am a novice.


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On Saturday, July 16, 2016 at 4:55:43 PM UTC+5:30, Bruce Esquibel wrote:

I hope that nothing has happened to the picture tube as it is not
replaceable. But If the fault does exist in some component of the picture
tube then is that component replaceable / repairable or not?


The picture tube in that thing is not the only part that isn't made anymore.


Yes, you are correct. Its very sad thought.


I'd guess at this point (10-12 years old) that everything in the parts list
for it are marked NLA.
Why Sony has done this? Is this to force customers to move to LCD TVs?


-Ronald
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Default Sony CRT TV not switching on

On Friday, July 15, 2016 at 11:14:21 PM UTC+5:30, wrote:
I have got a Sony Wega Flat CRT TV €“ KV-AR21M83. One day its picture gone bad. Before this it never gave problem. Its picture started to give disturbance, coloration problem, colour bleeding and also sometimes gave noise. So, I stopped using the TV but occasionally I switched it on to see its situation. I called a technician from Sony but he told that he does not know that where the fault is and Ill have to take it to service centre but I did not take it. One day I again switched it on but suddenly the disturbance increased. So I got frightened and turned it off. When I again switched it on the TV started to operate normally. But another problem came up. Whenever I switched on the TV and before the picture came on the screen, the TV displayed a green colour glow and also green coloured horizontal lines on the screen appeared for about 2 seconds and then vanished. The lines were not completely perpendicular. The lines were somewhat slanting, raised from the right side. The picture itself was fine but maybe with somewhat reduced colour accuracy. I felt it so. I could be wrong. Anyways, I used the TV for 1 - 2 months and then closed and covered it as I was using another TV.

After few months, I needed to use this TV again. So I switched it on. But the TV did not switch on. This was very much unexpected. Only the LED light on the TV blinks 8 times in red. I searched to see that do these blinks indicate something. I found out that 8 blinks as in my case indicates problem with audio IC IC406. But there was no audio problem in this TV. Only picture had issues.

So, what exactly has gone wrong in the TV? Is it the same component which is responsible for TV not switching on and the earlier picture problems?

I hope that nothing has happened to the picture tube as it is not replaceable. But If the fault does exist in some component of the picture tube then is that component replaceable / repairable or not?

Please Help. I am a novice.


UPDATE: I called a technician who has earlier fixed my other Sony TV. I did not tell technician about the earlier problems and neither the tech asked about it. When the technician opened the TV, he tested components on the PCB using multi meter. The technician felt that it could be due to moisture. So he tried to remove moisture but this did not help. So, it was not due to moisture. Infact there was no moisture inside the TV. Then he told me that its IC called function IC has damaged but that one is unavailable. But the tech told that he will get it from somewhere. After few days the technician told me that he asked someone about the blinks and came to know that it was due some other IC. Not the one he earlier told me. This means this technician who repairs TV never encountered this problem and could not correctly diagnose the fault. its strange. Anyways, he assured that he will come back after few days and will repair it. But he didn't turn up. I tried to contact him but he even refused to communicate. Maybe he did not get the part or he is unsure of the fault the TV has got.

The I asked at a TV repair shop. The person at the shop asked me that whether before the TV stopped working did it start giving green colour. I told him - Yes, green coloured line during statup for 2-3 second just before picture appeared. He told me it seems that its Extra High Tension Transformer has damaged. The transformer provides high voltage to the picture tube. To confirm, it took the TV to the shop. The person checked it using multi meter and confirmed that its EHT transformer has indeed damaged while the picture tube is fine. But even this transformer is no more available.

So, one technician told that its IC has damaged while another one told me its EHT transformer has damaged. Who is correct?

The symptoms - Disturbance in picture, later a fine picture but green glow and green raster line for 2-3 seconds during starup, then later on TV not starting up and blinking red light. These symtoms indicate an IC or Transformer failure? Please help.




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"Thanks but what is AKB? "

Automatic Kinescope Bias
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You are getting ****ed. You probably have a bad CRT and damaged circuits due to that. Return the favor and make them pay to dispose of the unit. just quit answering when they call The television is worthless.
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Default Sony CRT TV not switching on

On Monday, July 18, 2016 at 1:29:54 PM UTC-4, wrote:
On Friday, July 15, 2016 at 11:14:21 PM UTC+5:30, wrote:
I have got a Sony Wega Flat CRT TV €“ KV-AR21M83. One day its picture gone bad. Before this it never gave problem. Its picture started to give disturbance, coloration problem, colour bleeding and also sometimes gave noise. So, I stopped using the TV but occasionally I switched it on to see its situation. I called a technician from Sony but he told that he does not know that where the fault is and Ill have to take it to service centre but I did not take it. One day I again switched it on but suddenly the disturbance increased. So I got frightened and turned it off. When I again switched it on the TV started to operate normally. But another problem came up. Whenever I switched on the TV and before the picture came on the screen, the TV displayed a green colour glow and also green coloured horizontal lines on the screen appeared for about 2 seconds and then vanished. The lines were not completely perpendicular. The lines were somewhat slanting, raised from the right side. The picture itself was fine but maybe with somewhat reduced colour accuracy. I felt it so. I could be wrong. Anyways, I used the TV for 1 - 2 months and then closed and covered it as I was using another TV.

After few months, I needed to use this TV again. So I switched it on. But the TV did not switch on. This was very much unexpected. Only the LED light on the TV blinks 8 times in red. I searched to see that do these blinks indicate something. I found out that 8 blinks as in my case indicates problem with audio IC IC406. But there was no audio problem in this TV. Only picture had issues.

So, what exactly has gone wrong in the TV? Is it the same component which is responsible for TV not switching on and the earlier picture problems?

I hope that nothing has happened to the picture tube as it is not replaceable. But If the fault does exist in some component of the picture tube then is that component replaceable / repairable or not?

Please Help. I am a novice.


UPDATE: I called a technician who has earlier fixed my other Sony TV. I did not tell technician about the earlier problems and neither the tech asked about it. When the technician opened the TV, he tested components on the PCB using multi meter. The technician felt that it could be due to moisture.. So he tried to remove moisture but this did not help. So, it was not due to moisture. Infact there was no moisture inside the TV. Then he told me that its IC called function IC has damaged but that one is unavailable. But the tech told that he will get it from somewhere. After few days the technician told me that he asked someone about the blinks and came to know that it was due some other IC. Not the one he earlier told me. This means this technician who repairs TV never encountered this problem and could not correctly diagnose the fault. its strange. Anyways, he assured that he will come back after few days and will repair it. But he didn't turn up. I tried to contact him but he even refused to communicate. Maybe he did not get the part or he is unsure of the fault the TV has got.

The I asked at a TV repair shop. The person at the shop asked me that whether before the TV stopped working did it start giving green colour. I told him - Yes, green coloured line during statup for 2-3 second just before picture appeared. He told me it seems that its Extra High Tension Transformer has damaged. The transformer provides high voltage to the picture tube. To confirm, it took the TV to the shop. The person checked it using multi meter and confirmed that its EHT transformer has indeed damaged while the picture tube is fine. But even this transformer is no more available.

So, one technician told that its IC has damaged while another one told me its EHT transformer has damaged. Who is correct?

The symptoms - Disturbance in picture, later a fine picture but green glow and green raster line for 2-3 seconds during starup, then later on TV not starting up and blinking red light. These symtoms indicate an IC or Transformer failure? Please help.



Not sure how or why the tech thought the EHT/Flyback would give a green picture before failing. I fixed thousands of those and never saw that happen.

Anyway, the smart money is on Jurb's guess. The CRT has some leakage and arcing causing the AKB circuit to have some fits. Eventually, the IC on the CRT socket board shorted out (not uncommon) and taking out the supply from the main board. If you replace the IC and resistor (IIRC), the TV will run until the new IC gets whacked again. Sony had a bulletin that would improve the life of the IC by adding a diode across an inductor on the CRT socket board, but that won't help a visually leaky CRT.

And while I agree that it's time to move on with regards to this particular Sony, anyone who thinks moving to a new TV will stop the bleeding is mistaken..

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wrote:

Why Sony has done this? Is this to force customers to move to LCD TVs?


That's the easiest explanation to keep the conversation short.

In reality, in my opinion anyway, I really doubt most tv's after the early
1990's just were not made to be repaired.

I remember somewhere in that time frame ordering a schematic for a recent
Zenith tv and just getting a 10 page "leaflet", with almost no information.
It had block diagrams in gray and white shading. Basically if the fault was
in one of the gray shaded areas, you replaced the whole module, not parts.

So even if you knew it was IC401 of the 201-778 module, you couldn't order
just the IC401. Once the tv's that used that module were out of production,
that pretty much spelled the end of repairing it.

The other thing I've seen is even if replacements are available, it's
possible they ended up in a landfill somewhere. Mits here in the states used
to be marketed as MGA, they pulled out of the North American region
somewhere in the 80's (I think), all the parts in the depot in California
for the national distribution got trashed.

Big tax write off. If they would of tried to auction or sell the stuff for
one cent on the dollar, the tax write off was more profitable.

Odds are, most of the replacement parts for that tv you want to fix were not
available the day after you bought it.

It sounds strange to say that but from the 1990's, it seems most sets were
replaced with models that bore little internally to the earlier generation
of them. Back in the 50's and 60's there were chassis that were in
production for years. Some were used in tabletop models as well as consoles
with little changes. Eventually they would come up with "new and improved"
with a total redesign, but that took years usually.

Since the mid 90's it seems to me most chassis designs got tossed as soon as
the new ones came out a year later. Yeah, of course there were parts that
carried over from one to another, but for the most part they didn't. And
again, even if you identified the bad part, it doesn't mean it was available
as a replacement part.

So basically you are under the incorrect assumption that there was a
stockpile of replacement parts where there was never one at all. Once that
tv was out of production and the warranties expired, that about wraps it up.

You got 10-12 years out of it, consider yourself lucky and move on.

-bruce

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Mark Zacharias wrote:

My shop was servicing crt sets to component level up until 2005 or so; and
even a few since. Sony and Pioneer provided complete schematics and training
materials for all of their crt-based sets to authorized service centers. So
did Thomson. (GE and RCA - ugh)


And although we did not regularly service Toshiba, Hitachi, etc, we were
able to get service data when we needed it.


Zenith did take the opposite view, and used mostly non-serviceable modules.


I'm sure there are a 1001 exceptions to what I said, but you have to admit
after the mid 1990's, things did change.

The key phase to what you wrote is "authorized service centers".

It used to be mostly independent shops that did repairs prior. Sure there
were the crooks and ones that did poor servicing but after the mid/late
90's, most (both good and not good) all disappeared leaving only the
authorized ones, mostly because of the parts distribution getting locked up.

Here in Chicago, not counting tv repairs shops, we used to have at least a
half dozen parts stores. Some handled GE, some Zenith, RCA, Panasonic. If
you walked into one for a part and they didn't have it in the back, they
would let you know when you could pick it up.

When those places started to go under one-by-one, the writing was pretty
much on the wall that independents in the repair business were going to fail
too. No parts, no repairs.

I mean it's like owning a car, sure you can take it into the dealer
everytime for service and know you are paying top dollar for it but
independents, even though they may not have the latest and greatest with
service info, they still could do a reasonable repair for a reasonable
price.

Why the tv manufacturers wanted to go down the same path does seem to
support the conspiracy of "they want you to buy new, not fix", but that's
just my opinion.

I mean I know the technology changes to where repairing some things just
doesn't make sense. Like take plasma and dlp tv's, those are barely 10 years
old now tech wise and are totally obsolete.

-bruce

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