Quote:
Originally Posted by vortalexfan
Yes, all the diodes checked fine yet. The only diodes that checked bad was the bridge rectifier, which I already changed that out for a modern replacement the switching transistor I have not had a chance to check yet, the way they did the power supply in this VCR is that you have to disconnect a ribbon cable that's connected in a strange manner and then undo 2 solder blobs holding it to the main circuit board and then bend a retaining tab and then gently remove it from the main board without cracking the main board.
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Yes I've seen the process of removing the power supply in these machines. What I'm thinking is perphaps the caps in the primary side failed and caused the oscillator to go into a runaway condition and that caused the output voltages to rise up way too high to the point where the crowbar shorted and took out the switching transistor and other critical components. I've heard this can happen with Panasonics of this era.
03-17-2022, 02:17 PM
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