Polaroid ttm-2401 Won't Stay On

[BradyT]

As suggested by the header, I'm trying to fix an intermittent problem on a Polaroid ttm-2401 (old style crt ). Sometimes it will come on and work normally, sometimes it will shut down after a half hour of use. More often, it will turn on, immediately shut down, then try to "reboot" several times. In normal operation, a time delay relay will click about 5 seconds after turning the set on. When the set is acting up. the relay will click in the usual manner, then chatter and drop out. This cycle will repeat itself several times, after which the set has to be unplugged before trying again. The symptoms are similar to that of an overvoltage protector kicking in, but I'm working without a manual or schematic. I've looked for the usual problems -such as broken solder joints ( found several but no change ), open power resistors, and bad caps. When the set is working properly, no amount of component wiggling or pc board flexing will cause a problem. I'm also wondering if there is some way that the remote circuit could be acting up. I do have an electronics background but very little tv experience. Anybody out there ever have a similar problem?

[truetone36]

It sounds like the relay is starting to fail.

[zeno]

Chassis picture !!! That way we may know who built it.
Most the time int shut down after warm up is a cold joint.
Try tapping around. Most sets will shut down for:

No vert sweep
Over current from bad FBT or short on its secondary.
Too much HV caused by power supply usually.

I would look at the vert IC for bad cons first. Relay
chattering may point to an electrolytic on the coil supply.
Also check around the hoz drive xform & hoz out.
There are a ton of posabilities, sometimes even with a manual
shut down can be a bitch to find.

73 Zeno