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#1
02-05-2021, 02:05 PM
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Entry level 19" Zenith color TV from 1984
Here's a set that someone gave me, years ago, and it worked; but, I was not impressed with the picture. The color demodulation seemed off and I solved that problem by jumping two pins on connector 2B7. At that point, the set had a good picture and i put it into storage.
Fast forward a few years, and the set I was using at the time (a 19" Thomson-era GE with a CTC136 chassis) popped it's flyback. At which time, I pulled out the Zenith and it now had a solid green raster with retrace lines, due to a leaky video output transistor. After replacing that part, the set was ready for service. After a few months, the set developed an intermittent problem where the sync would go crazy and the picture would become severely overloaded (AGC issue). I fixed it by re-soldering everything in the AGC/IF area, and removing the IF/AGC IC from it's socket and soldering it to the chassis. Years ago, I learned my lesson with intermittent IC sockets, when I had a Curtis-Mathes drive me up the wall and it was a bad IC socket. The set has been working for months now and so far, no problems. This set uses a 9-181 signal module, a 9-186 horizontal sweep/HV module, and a small kick-start board. The cart is one that I bought at a church rummage sale and I think it's like the cart that one could buy to go with these sets.
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http://www.youtube.com/user/radiotvphononut 
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#2
02-05-2021, 02:41 PM
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Nice, and a nice sturdy cart.
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#3
02-05-2021, 03:58 PM
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Ah yes the "Custom" series sets. The first time I saw one it looked
cheap for a Zenith. I was not happy with the pix at all also. Went to the service manuals & found out why. We started modifying every new set that came in. I proudly told Roger Eaton the Zenith service rep for most of New England. He told me never tell Chicago & I know nothing ! With the mod they looked very good & held up very well. Jungle IC sockets were trouble on Sanyo / Sears, NEC, & Fisher. Often got cold joints without a socket also. Better sets used a 9-214 board that worked fine. Had a comb filter & AKB. Known as "Advanced System 3" They threw a fantastic pix. Enuf fer now 73 Zeno  LFOD !
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#4
02-05-2021, 06:32 PM
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Quote:
What did you come up with?? John
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#5
02-06-2021, 09:56 AM
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Easy. The bad looking ones all didnt have a auto color switch. With
auto on the colors suck. When the switch in off it grounds one of the IC pins. So you just run a ground from the secondary control plug blank pin over to the IF shield. IIRC Hitachi made that IC & I remember they had an orangy pix at that time but not so bad. Quote:
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