Saevar,

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I used to troubleshoot Solid State CRT power supplies. Replace the fuse and any shorted components that drive the HV transformer. Use a variable

power supply and bring up the voltage slowly to the HV output semiconductor. Monitor the output waveform of the semiconductor(usually the collector) with

an oscilloscope (max range setting). ?The waveform should have *no* small spikes or otherwise called ringing observed in between the higher amplitude

ones. If you have ringing I would suspect the transformer as having shorted turns. With a bad transformer, as the voltage increases the unwanted spikes

continue to grow. This condition usually causes the final semiconductor to fail(short) and then blow the fuse.

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Some HV output sections have a damper diode in this area that also fails.

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I don’t have the schematic in front of me but you can use this for a general approach. ?

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If this test appears to look fine, then possibly on the output of the transformer you will find a HV Tripler circuit that could be faulty. The Tripler

semiconductor device could be self-contained or an arrangement of HV diodes. As the name implies the Tripler multiplies the DC voltage that

connects to the CRT. Having a high voltage probe is the key to measuring the anode voltage on the CRT.

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Dave

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>Have you had a high voltage transformer be damaged or do you have any good idea how I can verify whether it is working or not? I can't see any induction >values nor turn ratio of the transformer in the troubleshooting manual so I don't know what are normal values.