pentiumspeed wrote on 2021-10-13, 00:56:
Zenith is worst of all using their specially designed semiconductors and Zenith also used their unique part numbers and they have very bad about the solder joints. When I get any of these Zenith at former job eventually hated them so much as I had to fix to their liking. Some keep coming back, Ditto to their arcing CRTs killing vertical IC. True story. I finally put repair ban on them.
Mhh this reminds me of the old TV repairmen's motto back then in the 1970s, 1980s "Von Mende, da lass die Hände" (From [Nord]Mende, leave off the hands).
There were some brands I never picked up when I was at school and earned a lot of money by collecting TV sets from the street, repairing them and selling the good ones.
Notably, Blaupunkt, Nordmende, Saba, and the like were mostly bad (and got much worse after being bought by French consumer electronics giant Thomson).
In America these brands probably are little known.
I usually just vented them just for fun (I think everybody loves the hissing noise 😀 ) when I found them, and took the HV cascade and thyristors or tubes (but only those of good brands like Valvo), unless they were very new and there was an acceptable chance that the CRT were not too worn out.
To be just, Saba was not bad before they got bought, their 1967 first color TV was extremely good.
It had separate HV and horizontal deflection circuits. The HV was always stable, no annoying picture size variations depending on the image changing. Absolutely ideal for home computers, too. If it were not that heavy, I'd have got myself one back then. Today they are very very rare...
Maybe you know Philips? These were infamous for their bad PCBs. Traces lifting off by themselves, getting micro cracks (leading to lack of continuity), and replacing components took extreme attention/required extreme care to avoid the traces going off. Aside of that, they were usually quite good.
Other brands I really liked to repair were, for example, Grundig and Loewe. Good quality, not cramped, it was easy to take measurements and replace parts, repairs normally went quick and smooth.
What you wrote about the resistors used by Zenith sounds like cheap ones that oxidize even at the soldered wire part. Such bad stuff was not even used by the worst German manufacturers... but, well, the worse ones used tube sockets that one occasionally had to be treated with aggressive flux material to get them resoldered for acceptable/good contact.
What was even more annoying with these particular brands was their "quick start mode" with continuous cathode heating.
Weak cathodes and 24/7 heating, the CRT were often trash after only 2 years.
Well, I guess then such must have been typical for Zenith back then, too 😀
So I guess the best advice for the OP might be to enjoy the venting noise and get some decent TV
