Hi folks,

I have 1990 SONY TV KV-X2531D/AE1C which has started to
drop video intermittantly from about 2 months ago. H/V
and stuff are okay (I can get a picture from teletext, but
with green missing). I traced the problem to the video
(B-) board. When I would cool down IC301/TDA4580 with
freeze-spray I could bring back video. So I decided to
buy a new 4580 off eBay (the part is actually new) for
10 Euros and had the IC replaced by a professional
who has the proper re-/soldering equipment. He soldered
a IC-socket instead of the IC for easy replacement. So
I replaced the board and fired it up again, and everything
worked perfectly --- for 3 hours . Then the same problem
would occur again, so the IC was not the souce.

In the area of the IC (to be hit by the freeze-stream) was
also a cap and some diodes which I tested with an ESR-meter and a
DMM respectively. Can the cap still be the problem even when
its ESR is okay (about 0.2 ohms) ?? Any other hints ?

Adrian

I have had a number of Sony sets with defective CRT's that were blowing the
video drive IC. The CRT was arching in side, and thus damaging the drive IC.

--

JANA
_____


"Adrian Glaubitz" wrote in message
...
Hi folks,

I have 1990 SONY TV KV-X2531D/AE1C which has started to
drop video intermittantly from about 2 months ago. H/V
and stuff are okay (I can get a picture from teletext, but
with green missing). I traced the problem to the video
(B-) board. When I would cool down IC301/TDA4580 with
freeze-spray I could bring back video. So I decided to
buy a new 4580 off eBay (the part is actually new) for
10 Euros and had the IC replaced by a professional
who has the proper re-/soldering equipment. He soldered
a IC-socket instead of the IC for easy replacement. So
I replaced the board and fired it up again, and everything
worked perfectly --- for 3 hours . Then the same problem
would occur again, so the IC was not the souce.

In the area of the IC (to be hit by the freeze-stream) was
also a cap and some diodes which I tested with an ESR-meter and a
DMM respectively. Can the cap still be the problem even when
its ESR is okay (about 0.2 ohms) ?? Any other hints ?

Adrian

Hello,

I have had a number of Sony sets with defective CRT's that were blowing
the video drive IC. The CRT was arching in side, and thus damaging the
drive IC.


Uh oh, that sounds like a big problem. But the thing is, the picture
will sometimes come back, i.e. it is an intermittant problem. Also,
isn't the CRT driven by the transistors on the neck board ? Can
the CRT still then kill the jungle IC ?

Adrian