[kx250rider]

To add to the opinions above, you have the best TV ever built. The Zenith 25DC56/57 was one of the last 100% Chicago-built Zeniths, and also one of the last hand-wired by the hands of the women of the Rosie-the-Riveter era.

The FIRST thing that comes to mind, (although this would have to assume that you do indeed have high voltage and you believe you don't), is the Chromatic switch. It's a nightmare when it's dirty, and causes blacked out screen, flickering, color problems, etc. Just to rule that out, maybe turn the set on, and fiddle with the Chromatic button and see if you get anything. If not, then your first thought is probably right; no HV.

If you lost high voltage, it's very easy to troubleshoot, and most everything is available for that set (either new or from other AKers). If that one has a circuit breaker, and it's tripped, you likely have either a bad tripler, or possibly a shorted horizontal output (or both). Remove the 2 screws from the horizontal output (thus disconnecting the collector), and reset the breaker (or change the chemical fuse), and then see if the 130 volt line is live. I think you can find the 130v on the case of the regulator transistor mounted next to the flyback (see the diagram in the cabinet). If the 130 volts is back, then remove the horizontal output and measure it from collector to base and collector to emitter, and see if any direction is short. If so, you likely just have a failed transistor 121-831 (or NTE 165). If the transistor isn't shorted, put it back, and on the tripler, carefully peel off the rubber glob and unsolder the wire coming from the flyback and place the wire safely away from ground, and see if the set turns on, and you should hear a corona hiss from that loose wire. If yes, you have a bad tripler. At that point, I'd update the tripler to an NTE526A, which eliminates the focus divider and double anode wire.

Charles