JVC AV-28WT2EK television popped and died

[Colin Jones]

We have a JVC AV-28WT2EK which has been working perfectly until today.
For a few seconds before it died, the picture went squashed to the
bottom of the screen, there was a loud pop/bang then the screen went
blank.

If you switch it on now, it goes into standby, applying power via the
remote, there is a 'ping/hiss' noise from the tube, which then starts
to come through the speakers as well. This lasts a few seconds before
the TV puts itself back into standby. The screen stays steadfastly
black.

I did wonder with the pop if there would be anything visibly fried
inside, but cannot see any signs of 'explosions' or anything.

Having successfully repaired my VCR power supply after getting help
online (by replacing several capacitors), I wondered if I might be able
to do the same with the TV? Anyone any pointers - or ideas on what it
could be/what I should do first?

Cheers,
Colin.

PDF user manual
http://www.jvc.co.uk/files/instruction_manual/ib_av24wt2_28wt2.pdf -
don't seem to be able to find a service manual free online.

 

[Searching]

We have a JVC AV-28WT2EK which has been working perfectly until today.
For a few seconds before it died, the picture went squashed to the
bottom of the screen, there was a loud pop/bang then the screen went
blank.

*******************
If the picture went squashed to the bottom, it would appear that you
have a vertical deflection problem. I would check the vertical section
( the IC, caps)

 

[[email protected]]

*******************
If the picture went squashed to the bottom, it would appear that you
have a vertical deflection problem. I would check the vertical section
( the IC, caps)

The hissing sound sounds like an electrolytic going bad.

H. R. (Bob) Hofmann

 

[Meat Plow]

The hissing sound sounds like an electrolytic going bad.

Or a snake has crawled inside.

 

[Homer J Simpson]

Or a snake has crawled inside.

Sometimes it's only the snake that keeps it running.

 

[David Naylor]

We have a JVC AV-28WT2EK which has been working perfectly until today.
For a few seconds before it died, the picture went squashed to the
bottom of the screen, there was a loud pop/bang then the screen went
blank.

If you switch it on now, it goes into standby, applying power via the
remote, there is a 'ping/hiss' noise from the tube, which then starts
to come through the speakers as well. This lasts a few seconds before
the TV puts itself back into standby. The screen stays steadfastly
black.

I did wonder with the pop if there would be anything visibly fried
inside, but cannot see any signs of 'explosions' or anything.

Having successfully repaired my VCR power supply after getting help
online (by replacing several capacitors), I wondered if I might be able
to do the same with the TV? Anyone any pointers - or ideas on what it
could be/what I should do first?

Cheers,
Colin.

PDF user manual
http://www.jvc.co.uk/files/instruction_manual/ib_av24wt2_28wt2.pdf -
don't seem to be able to find a service manual free online.

This unit is well known for the 200. or 2220 m at 200 volts cap in the
power supply going back look at the largest electroletic cap towards
the right and see if the top looks puffed up. if not check the others
But I would bet that , that is the problem

 

[Colin Jones]

power supply going back look at the largest electroletic cap towards
the right and see if the top looks puffed up. if not check the others
But I would bet that , that is the problem

Unfortunately none of the electrolytic capacitors (as far as I can
tell) have any *visible* problems with them - I have scrutinised the
whole board pretty carefully! I have a small analogue multimeter, and
was trying to follow the FAQ instructions for testing them here:
http://www.repairfaq.org/sam/captest.htm - it does appear to go over to
the right, then charge slowly up to infinite - I couldn't quite work
out from the FAQ what is supposed to happen if the polarity is reversed
- the multimeter just went over to the right but did not really move,
but I am only following the info - so may not be interpreting the
results correctly!

There is some power as when it is on, the red standby LED is on, and
you can use the remote and switch on the set. When you do this the
other LEDs on the front all come on as usual, and there is a purple
glow from the tube, but coupled with a nasty crackling noise, and the
set switches back to standby after a few seconds.

When it is in standby there is a very quiet 'tick-tick' sound from the
right-hand board. I've heard that this is a capacitor type noise as
well? However I don't know whether this is 'normal' when in standby or
whether it should be totally silent?

 

[Cliff Top]

The clue to your problem perhaps lies in the symptom just before it died. I
would suspect the frame drive IC, since you say the picture squashed down.
It is also possible that one of the low voltage regulators may have a
problem too..
In my experience with all JVC sets, I haven't had any real problems with
electrolytics on these sets- frame ICs however are more common..
The set is now trying to run up with a shorted/faulty IC thus as it fires up
and voltages come up, you get the eht rustle etc, but then the current
protection cct is detecting a fault and tripping the set for safety. The
ticking is the set running normally in standby/burst mode just to give some
voltages for micro and remote operation.

If you want a pdf service manual email me and I'll send it to you. (at your
risk of course)

Cliff Top