Occasional Power Problem with Zenith System 3

[NowhereMan 1966]

I had a problem with my 1982 Zenith System 3 today, when we turned it on, only the green LED channel number came on and that was it. We unplugged it and several hours later, we turned it on, no problem. Could I be having a high voltage problem with it? The specs are:


Zenith

SY2585P2

175-2030 tuner
9-190 module
9-186-01 module high voltage
9-181-02 module
9-181 universal replacement
204-860-0211 tube

[radiotvnut]

I was afraid something like this would happen to that set.

On the heatsink with the horizontal output transistor, is there a small circuit board with a single orange wire going to the 9-186 HV module? Most sets used this start-up board but some early ones did not. If yours has the board, replace the electrolytic capacitor on that board. I've known them to cause erratic/no start-up. Other than that, look for any bad solder connections on the main module and the HV module. I think there are some stand-up power resistors on the main board that will break free from the board due to heat. Resolder these. Also, there could be problems with the power relay (loose connections or a faulty relay).

Other than that, I don't know much else. These were good TV's; but, could be a BITCH to troubleshoot. I've seen the main board fail and take out the HV board and the other way around. I've had plenty of known bad 9-186's and I was only able to fix one (besides the usual solder connections) by changing a driver transistor. I've seen those parts on that board check fine but the board would not work in a set. It finally got to the point I would not fix one of these if it was not the obvious. If it was a set that belonged to someone, I'd give an estimate for both modules.

Good luck on fixing this one and if anyone has any troubleshooting information on these chassis, we'd all love to hear about it!