Advice needed for "daily driver" Zenith set

[radiotvnut]

There's a resistor pack in the video output circuit, on the main module, that can develop loose connections and cause that problem. Also, check the soldering on the interconnect cable between the main module and CRT socket module.

I've replaced a lot of those 9-181 and 9-186 modules. Back in the early-to-mid '90's, I could get them for around $50 each. Back then, it wasn't so bad to spend $50 on a module when you could sell the set for $100-$125. Then, the prices started going up and up and the value of the TV's kept going down, down, down. About 8 years ago, I think those modules were over $100 each. You probably can't even get them now. I remember getting one of those sets that would hiss, groan, and grunt like it wanted to come to life. All voltages were low. I finally chased the problem down to a dead shorted electrolytic cap inside the electronic tuning module. It was something like a 1000uf, 25V. There is also a little cap on the start-up board that will cause a dead set.

Sometimes, I've found both the main and sweep modules to be bad. If you're not careful, one module can fail and take out the other one. When in doubt, I just changed both boards. And, I was usually in doubt more than I was certain on those models.

The 9-160 based sets were about as bad. I remember one non-remote, cable ready System 3 console that was given to me that was dead. Quickly found a blown fuse and a shorted HOT. Replaced all that and resoldered some loose connections and it would try to come to life. Upon digging deeper, I replaced a bunch of other blown parts on the 9-160. When I fired it up that time, the flyback literally fired up! I shut it off quickly before I fried any parts, found a good flyback from a junk board, and fixed the set. It had a nice picture when I was finished; but, it was sure a PITA to get it to that point. It would have been easier to swap the 9-160; but, they were getting high dollar at that point and consoles were getting harder to sell. This was in the late '90's. I believe those 9-160 sets caused a lot of house fires as a result of the flyback catching on fire, which in turn, caught the cabinet on fire.