[Chad Hauris]

The series light bulb is a good suggestion where a short circuit is suspected, but since you have sound the power supply is probably ok.

Here is how I test for HV:

First, get a neon bulb tester like you use to check for 120 volts ac at an outlet. Hold the neon bulb carefully near the output lead of the flyback with set on. Keep fingers away from the HV components. Just hold the bulb near it...no direct connection. If it lights there is AC coming out of the flyback.

2. If there is no lamp indication, hold the bulb near the insulation of the Horizontal output tube plate lead. If the bulb lights here, the primary portion of the flyback (Horiz. tube and damper) are working. If no light indication proceed to step 3.

3. REMOVE the plate cap from the horizontal output tube. Make sure that it is not connected to the tube. Connect the voltmeter to the disconnected plate lead. You should have the B+ voltage, around 280 volts. If there is no voltage, either the damper is not functioning or the flyback winding is open. In such case, check the damper plate for B+ voltage.

4. If there is plate voltage at the plate cap hook it back up and measure for negative grid voltage at the Horiz output grid. There should be around -30 to -50 volts. No negative voltage indicates the horizontal oscillator is not working. Don't run the set for long like this as the horiz output tube is drawing too much current and you can burn out the flyback winding.