Zenith "Panarama" System 3 Help

[jstout66]

I finally found a Zenith "Panarama" set. It's a System 3 from March 1979. Model K2540X.
It had a good picture, but the pix would turn green once in awhile, but if you smacked the set would go back to normal. I took the back off to test the picture tube (25VETP22) which tested fine. I figured loose connection so I just made sure everything was connected firmly. Powered the set up, and now I have no vertical, just a thin line in the center of the screen like it was in "service mode" Anyone have any ideas?
The modules in the set (which I could barely make out) are 9-155 (video board that plugs into pix tube. 9-152-02 (not sure what that one does) 9-151-01 (tuner) and 9-153 (high voltage board)
Does anyone still have any of those modules laying around. Thanks!

[Sir.Byrd]

That is a nice looking set!

[zenith2134]

Hey there jstout. Nice set indeed! Like those alot.

Last '79 I picked up would go red intermittently. I re-flowed the solder joints on the crt base board and also cleaned every single module connector with 91% rubbing alcohol. Along with cleaning out the service/user controls, this may be all it needs. I have probably 'fixed' 3 or 4 80s system 3s this way in the last few years. Good luck! (P.S. I'll look for those boards but they don't ring a bell...)

[radiotvnut]

There is a large resistor network on the 9-155 video module that probably needs to be resoldered. Also, resolder all three video output transistors on this module. Or better yet, resolder everything on the module.

As far as the vertical problem, I seem to remember a 9-152 having bad solder connections around the vertical output transistors. Those are the transistors located on the heatsinks. There could also be a defective electrolytic cap in the vertical circuit.

Those pesky edge connectors were also prone to fail. Clean them very well with Deoxit and make sure they are making good contact with the module.

I know I don't have any boards left for these sets. I have not done any serious troubleshooting on one in years.

Your version with the 9-153 HV module and the self regulating power transformer is not a very common set. That was the first generation System 3 chassis and was only made for a year and a half at best.

The second generation System 3 chassis used a 9-160 power supply / HV module in place of the older 9-153 and the power transformer. All other modules are the same.

[jpdylon]

I have a whole box of system 3 and cc II modules in storage. Give me some spare time to dig it out and I'll see what I have.

[NowhereMan 1966]

Originally Posted by zenith2134

Hey there jstout. Nice set indeed! Like those alot.

Last '79 I picked up would go red intermittently. I re-flowed the solder joints on the crt base board and also cleaned every single module connector with 91% rubbing alcohol. Along with cleaning out the service/user controls, this may be all it needs. I have probably 'fixed' 3 or 4 80s system 3s this way in the last few years. Good luck! (P.S. I'll look for those boards but they don't ring a bell...)

I know, my 1982 model does that every so often, sometimes it runs OK for many months, even a year or so, then she does that. We rest her for part of the week or a week and then she's fine again for a while. I think the last time she did it was early 2007, I'm not sure.

[NowhereMan 1966]

Originally Posted by jpdylon

I have a whole box of system 3 and cc II modules in storage. Give me some spare time to dig it out and I'll see what I have.

Yeah, if you can, I'll be interested in any modules that you are willing to unload.