Hello, all. After 11 years of trouble-free operation of the subject TV
the following has occurred within the last two weeks:

The set would periodically lose vertical sweep (single bright horizontal
line). Vertical sweep would often be absent upon power-up. Lightly
bumping the cabinet would often restore the sweep for the rest of the
evening's viewing but return the next day.

The set finally quit altogether with the power cycling endlessly on then
off until the line cord was unplugged. There was a very pronounced burn
smell emanating from inside the cabinet.

I removed the back of cabinet and as best my olfactory sense could
determine the burn smell is coming from what appears to be the RF
enclosure of one of the tuners (the set has two). There does not appear
to be any evidence of burned components elsewhere on any of the three
circuit boards.

Why the tuner would have anything to do with vertical sweep failure is
confounding. The suspect RF enclosure/assembly is located at the top of
the following vertically-mounted circuit board, which is marked (on its
underside) as follows:

At top left of board - JVC PWS 96.5.20 SOMEYA

At bottom of board - CKF0426-AS1-1 CMK-81X

Any help in facilitating repair would be greatly appreciated. Thanks so
much for your time and comment. Sincerely,

J.B.Wood:
If you would have had this fixed before it quit altogether a shop
probably could have done the repair for about $40 to $60 or so....
resoldering connections near and around the vertical deflection output
circuitry and flyback derived B+ supply and may replacing some high
ESR electrolytics.... now that the television has quit altogether
and there is a burnt smell the repair and parts price will be much
higher and extent of the repair will be much more involved.
From the sounds of you questions and how you handled the faultering
television to start with it sounds to me like you are way over you
head on this one. My advice is that you take it to a repair shop for
at the very least a repair cost estimate so you can make an
intelligent repair deciesion with real numbers from a real tech who
opened the set and make tests and measurements.
If you want to further investigate a DIY repair you should go to the
website for this newsgroup at
http://www.repairfaq.org/
There, with some search time, you will find a wealth of
troubleshooting, testing, repair and IMPORTANT SAFETY information
regarding television repair proceedures.
Best Regards,
electricitym

In article .com,
wrote:

J.B.Wood:
If you would have had this fixed before it quit altogether a shop
probably could have done the repair for about $40 to $60 or so....
resoldering connections near and around the vertical deflection output
circuitry and flyback derived B+ supply and may replacing some high
ESR electrolytics.... now that the television has quit altogether
and there is a burnt smell the repair and parts price will be much
higher and extent of the repair will be much more involved.
From the sounds of you questions and how you handled the faultering
television to start with it sounds to me like you are way over you
head on this one. My advice is that you take it to a repair shop for
at the very least a repair cost estimate so you can make an
intelligent repair deciesion with real numbers from a real tech who
opened the set and make tests and measurements.
If you want to further investigate a DIY repair you should go to the
website for this newsgroup at
http://www.repairfaq.org/
There, with some search time, you will find a wealth of
troubleshooting, testing, repair and IMPORTANT SAFETY information
regarding television repair proceedures.
Best Regards,
electricitym

Thanks for the response! You make some excellent points but I doubt a TV
repair shop these days spends a lot of time troubleshooting and soldering
at the board component level. There's just too many surface-mounted
components to deal with. I suspect if the shop can trace the problem to a
board assembly it becomes a swap out issue. Then there's the issue of
whether that board is available for an 11 yr old set. If that faulty card
cannot be replaced then the shop would probably say the set's not
repairable (or alternatively put, "you wouldn't want to spend what it
would take to put the set into working order").

I was hoping to get some insight into what board(s) might be at fault in
my set and then attempt a swap out. Sincerely,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

J. B. Wood wrote:
In article .com,

Thanks for the response! You make some excellent points but I doubt a TV
repair shop these days spends a lot of time troubleshooting and soldering
at the board component level. There's just too many surface-mounted
components to deal with.

Analog TVs have ALWALYS been repaired at the component level,
including smds.
No big deal to fix for a trained technician.

I suspect if the shop can trace the problem to a
board assembly it becomes a swap out issue.

Your TV has no replacable "modules". It is component level only. No
boards
are swapped out.


Typical carry in charge for a JVC with a burned vertical circuit is
under a hundred
dollars complete using OEM parts.

This set is rarely, if ever, repaired by replacing a board. The repair
should be very straightforward for most TV techs. Your assumptions are
faulty. You could spend several hundred dollars to buy the board, if it is
available. The repair should not be much more than $100 at the component
level. As you were told, you might have made it much worse by not dealing
with the very common intermittent solder connections until the more severe
failure occured. Get it to an experienced shop.

Leonard

Thanks for the response! You make some excellent points but I doubt a TV
repair shop these days spends a lot of time troubleshooting and soldering
at the board component level. There's just too many surface-mounted
components to deal with. I suspect if the shop can trace the problem to a
board assembly it becomes a swap out issue. Then there's the issue of
whether that board is available for an 11 yr old set. If that faulty card
cannot be replaced then the shop would probably say the set's not
repairable (or alternatively put, "you wouldn't want to spend what it
would take to put the set into working order").

I was hoping to get some insight into what board(s) might be at fault in
my set and then attempt a swap out. Sincerely,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337