Sony TV vertical interlace problem...

[Vector Viper]

I have seen this problem in many older sony sets, around 1992-1993, using
the chassis with the 3 stand-up cards (this set chassis also has the
imfamous Sony sound
module that goes bad too)
This particular model is a KV32TS20, but again, many models use these
modules...

The problem:the vertical sweep is perfectly stable, but the 2 fields do not
'lace' properly;
the interlacing acts 'loose' sometimes being aligned at the top or middle,
almost never the bottom.
Ajusting the height or the lin will make different areas be 'lined up'
something changes
between them so they don't register properly...everything is vertically
jumpy, depending on
screen position...this sets uses the TDA8302 ic chip for vertical
generation...
Swapping different cards can move the problem around, but not fix it...
has anyone ran into this? I figure a cap is at fault, and have checked the
obvious ones,
to no avail...
help ?

Viper

 

[Shoreline Electronics]

Probably a bad electrolytic in the 500 series vertical circuit OR poor B+
filtering to the vertical output. Check the caps on the +/- 15V supply
lines.


--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
jstielau@snet.net
==========================
"If you push something hard enough it will fall over."
Fudd's First Law of Opposition - Sir Sidney Fudd


"Vector Viper" <ahowald@w-link.net> wrote in message
news:vm0dmjaauke56f@corp.supernews.com...

I have seen this problem in many older sony sets, around 1992-1993, using
the chassis with the 3 stand-up cards (this set chassis also has the
imfamous Sony sound
module that goes bad too)
This particular model is a KV32TS20, but again, many models use these
modules...

The problem:the vertical sweep is perfectly stable, but the 2 fields do
not
'lace' properly;
the interlacing acts 'loose' sometimes being aligned at the top or middle,
almost never the bottom.
Ajusting the height or the lin will make different areas be 'lined up'
something changes
between them so they don't register properly...everything is vertically
jumpy, depending on
screen position...this sets uses the TDA8302 ic chip for vertical
generation...
Swapping different cards can move the problem around, but not fix it...
has anyone ran into this? I figure a cap is at fault, and have checked the
obvious ones,
to no avail...
help ?

Viper

 

[Vector Viper]

"Vector Viper" <ahowald@w-link.net> wrote in message
news:vm0dmjaauke56f@corp.supernews.com...

I have seen this problem in many older sony sets, around 1992-1993, using
the chassis with the 3 stand-up cards (this set chassis also has the
imfamous Sony sound
module that goes bad too)
This particular model is a KV32TS20, but again, many models use these
modules...

The problem:the vertical sweep is perfectly stable, but the 2 fields do
not
'lace' properly;
the interlacing acts 'loose' sometimes being aligned at the top or middle,
almost never the bottom.
Ajusting the height or the lin will make different areas be 'lined up'
something changes
between them so they don't register properly...everything is vertically
jumpy, depending on
screen position...this sets uses the TDA8302 ic chip for vertical
generation...
Swapping different cards can move the problem around, but not fix it...
has anyone ran into this? I figure a cap is at fault, and have checked the
obvious ones,
to no avail...
help ?

To add to this-I have 2 "A" cards, 1 has great interlace, one does not (top
about 2 lines out)
Yet I can see no difference in the vertical output signal or other
waveforms.
It's ON the A card!!! (Somehow)
It's not the TDA8302 ic, I took one off a bad board; the board still has
great lace right now,
as before...
Argh! It's JUST bad enough to be annoying on a 30"sony set, so the problem
can't be ignored-
argh!!!!!! ARGH!!!!!!!!!

Viper

Viper