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Old 05-26-2006, 03:13 AM
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blue_lateral blue_lateral is offline
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Join Date: Mar 2005
Location: Washington State
Posts: 530
Unfortunately, I think you have a dead short somewhere. My 9 is buried, so I cant really look at what youre looking at, but I would bet something is shorted in the voltage doubler. I'll bet it was drawing too much current if it blew that fuse wire up.

If you have a variac I would use it now. If not I would make a dim bulb tester. The power supply is a voltage doubler. The other 160mf cap could be shorted or one of the diodes could be shorted. You could bring it up slow and see if both halves of the voltage doubler have equal voltage (measure across each 160mfd capacitor). If not you should figure out why. The doubler makes around 400 volts under full line voltage. So about 200 volts per side at full line . On the dim bulb it will be a lot less, but shouldnt be a bunch on one side and nothing on the other.

If you want to kill the high voltage so you can run it on the bench, just remove the horizontal oscillator and horizontal output tubes.

There have been old threads about the thermistor. Apparently the sets work fine without. I wonder though, if the thermistor is gone is there anything else to act as a fuse?

I suspect that fuse wire thing may have just saved your power transformer.

All the best,

John
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