Zenith 25DC56 console TV acquired!

[radiotvnut]

Concerning your loss of HV, you can disconnect the lead at the tripler that comes from the flyback. Then, move this lead away from anything that it can arc to. Then, power up the set and if HV is getting to this point, you'll be able to draw an arc to a screwdriver, when you bring the screwdriver blade close to the end of the lead. If you get the arc, that means everything up to that point is good and your tripler is bad.

If you don't get the arc, that means no HV is getting to the tripler and there are a number of things that can cause this. Two common things are loss of B+ voltage to the horizontal output stage and loss of horizontal drive to the base of the horizontal output transistor. No horizontal drive can be caused by a defective horizontal oscillator module, no B+ voltage going to said module, or an open winding on the horizontal driver transformer. There are other things that can cause it; but, these are most common.

If you're getting no B+ voltage at the horizontal output transistor (should be around 120V-130V), the most likely cause is either an open winding on the flyback or an open power resistor that feeds voltage to the flyback.

The horizontal output transistor is likely still good because when they fail, they usually short and when that happens, the circuit breaker will trip.

While you're in there, that sloppy connection to the tripler needs to be redone and it would be a good idea to seal this connection with RTV (once the set is fixed).