Predicta Holiday - First power up attempt

[reichsrundfu]

Originally Posted by Phil Nelson

If your TV has all of its original capacitors, I'll put on my magical wizard hat and predict that you likely have a bad capacitor -- and more likely, a few dozen of them.

I wouldn't fret over the flyback at the moment. Some wax drip underneath it is common.

Many restorers would plunge ahead and start recapping, beginning with the (duh) electrolytic capacitors in the power supply. The schematic shows the voltages ("280V source" and so on) that the TV is supposed to produce downstream of the rectifiers and p-s filter caps. Set your variac at 117 volts and test those points.

Until your power supply is producing the basic voltages needed by the rest of the TV, trying to troubleshoot problems on a symptom-by-symptom basis can be frustrating and confusing.

What have you done to this TV up to this point? Tested tubes? Cleaned controls? It's helpful if you confine all discussion of your TV to one thread, so that people can read about it in context instead of searching around in multiple threads to get a clue about what's happening.

This article has some advice about basic first steps that may be useful:

http://antiqueradio.org/FirstStepsInRestoration.htm

If you have already done all of those good things, then recapping is next on the agenda. The only question is whether you want to do them all at once, or one-by-one (or few-by-few), powering up the TV periodically to see if you're making progress (or at least, not making things worse).

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Quite agree. I simply do not believe in powering up any radio or television receiver until ALL of the filter and paper capacitors--"all of them" being the operative-- have been replaced.

Did I mention all of them?? Powering up a receiver with original caps is in my very humble opinion, silky, lazy and risky. Heavy on the risky. Recapping your set fully will reduce risk tremendously. Then you can power it up and go looking for whatever else may be Ailing it, such as mica caps, resistor issues, etc.

[Electronic M]

Originally Posted by reichsrundfu

Quite agree. I simply do not believe in powering up any radio or television receiver until ALL of the filter and paper capacitors--"all of them" being the operative-- have been replaced.

Did I mention all of them?? Powering up a receiver with original caps is in my very humble opinion, silky, lazy and risky. Heavy on the risky. Recapping your set fully will reduce risk tremendously. Then you can power it up and go looking for whatever else may be Ailing it, such as mica caps, resistor issues, etc.

It is not all that risky if you do the power up right. A slow start with a variac, the back off so any smoke or signs of trouble can be seen, and periodically feeling the cans and transformer to make sure they are not getting hot is about all that needs to be done to give a safe test power up. (and of course having the sense to pull the plug if signs of trouble manifest)

It is always good to have a baseline before you start changing caps so that if you screw it up you know to check your own work, and not simply blame the set and start chasing shadows.