1981 Zenith System 3 problems

[dtryon]

Laserdisc,

Here is a link to a Triac's that will work great in your Zenith. I was a repair tech working on Zeniths for years and the Triac you want to replace is a very generic part,. Hope this helps: https://www.ebay.com/itm/10PCS-BTA16...4AAOSw32lYroTn Or cross this number to a NTE number.

Dennis

[Laserdisc]

Hey,for 10 for $3.50 I'll give it a shot. Mine has a blue GE branded one that didn't cross reference to anything so I couldn't find anything. One issue with the tv that I've neglected to mention here is that with a weak signal it has some light retrace lines and when showing a solid black screen with a good signal there are a couple of vertical lines in the middle of the screen, it looks like maybe a degaussing is in order if I can find a coil but the grainy picture and retrace lines concern me. Both are very minor and have not worsened with lots of use but I like this set alot for some reason and I want to fix any issues it has.

[zeno]

Change the 10mfd 315V cap near the FBT. Causes any of the following.

cant turn down brite
retrace lines
jail bars
pix dark to light across screen
smearing, streaking
" just not right" pix.

VERY common on ANY SS color TV. Can fool some into thinking CRT bad.

73 Zeno
LFOD !

[Laserdisc]

Strange that one cap can cause all of that,but that sounds exactly like the problems I'm having. I'll replace it and see how well it wakes up. Now that you mentioned the brightness part turning "picture" all the way down doesn't completely blank the screen like every other tv I have.

[Laserdisc]

That cap certainly improved matters! Cleaner picture,no retrace lines,brightness is now the expected linearity instead of a crap shoot,cool! The vertical lines are still there on a black screen but considering this thing sat in a window for almost 30 years in direct sunlight under a huge leak I suppose I should be happy the thing works right at all. Speaking of,when I had the 9-160 out to replace the cap I got a better look at the total damage,starting to get some board rot along the edge near the CRT,few more years under that leak probably would have finished it off but If taken care of should last a good long while.

[zeno]

For lines turn down the G-2 a little. Its the yellow pot
on the CRT board.