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  #1  
Old 01-16-2018, 10:30 PM
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1981 Zenith System 3 problems

I picked up this set from a closed down repair shop around Christmas,It sat on display in the front window since I believe 1989,in the sun,under a leak,yeah.... It works great aside from some minor gripes,it won't shut off,and with an amplified signal fed straight to it it's still a little grainy,like a good over the air signal almost. I know of the triac in the remote power supply that likes to short and that's the issue here,but where on earth do I find a replacement? None of the numbers on it cross reference. I've gone through this thing and cleaned the grounds and I'm wondering if I need to just take the plunge and recap it. It's a 9-160 set.
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Old 01-16-2018, 11:29 PM
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Here's some more pictures
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File Type: jpg IMG_20171209_143056035.jpg (76.1 KB, 44 views)
File Type: jpg IMG_20171209_142804099.jpg (91.9 KB, 39 views)
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Old 01-17-2018, 08:41 AM
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I would try a triac from earlier CC2 chassis its probably the same.
Seen NOS triacs on e-bay. They get subbed to a kit 800-###, I
dont remember all the number.
I wouldnt recap unless a problem. There is a 10mfd 315V on the
back edge by the FBT that always goes. I would remove the 9-160
& go over it for cold joints, there ARE some !
For the RF check the ant cable. Also the tuner plugs get cold joints.
On the IF board 9-151-# ? there is an AGC delay control.
Last check the CRT socket 9-155-01 for cold joints especially under
the white resistor pack & socket itself.

73 Zeno
LFOD !
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Old 01-19-2018, 09:58 PM
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I forgot to mention I cleaned up all the contacts in there as well. The antenna cable is in great shape. Next time I have the bench space I'll tear it down and go over everything for cold joints. Ok,AGC delay control,what is it's function and how can I adjust it properly? I have experience on electronics but I'm still learning,especially on TV's.

I see a Zenith Triac replacement kit on eBay part no. 800-618. It just looks like a cable in the bag, is there something I'm not getting about the replacement?

Last edited by Laserdisc; 01-19-2018 at 10:44 PM. Reason: omitted info
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Old 01-20-2018, 09:13 AM
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The cable plugs in series with the power wires ( black, blue, grey )
on older CC2 sets & has a VDR added. Should also have instructions
& triac & IIRC hardware, mica etc. Remember I am ASSUMING the
triac is the same !!!!!

RF AGC with strong signal turn untill snowy. Turn back until
it just clears up & leave it there.

73 Zeno
LFOD !
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Old 01-20-2018, 02:13 PM
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I ended up getting an nos remote module off eBay so we'll see what that does for it, right number and everything.
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Old 01-20-2018, 03:41 PM
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Quote:
Originally Posted by Laserdisc View Post
I ended up getting an nos remote module off eBay so we'll see what that does for it, right number and everything.
I like it ! Fast & easy. We only used the kits on the old sets that had a
massive tuner assy that cost like $80 exchange rebuilt. Come to think
of it I dont remember changing any of the small on/off modules !

73 Zeno
LFOD !
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Old 01-20-2018, 06:14 PM
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I usually like to troubleshoot and buy component parts but the right module nos for $10 seemed too good to pass up. I've also ordered that cap so when everything comes in it'll get blown apart and get some much needed TLC.
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Old 01-31-2018, 12:32 AM
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Well, wrong part number. Crap. Visually identical module but the number is different. Installed the set won't turn on,so back to the original for the time being until I can find a triac.
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Old 01-31-2018, 12:12 PM
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There is a module cross reference manual IIRC the CRSP that tells what will interchange. Someone posted it on vk.
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Old 03-02-2018, 09:53 AM
dtryon dtryon is offline
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Triac for Zenith

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
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Old 03-12-2018, 12:25 PM
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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.
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Old 03-13-2018, 08:17 AM
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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 !
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Old 03-13-2018, 10:16 PM
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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.
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Old 03-17-2018, 09:00 PM
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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.
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