Re: Few questions on fixing a 7623a power supply.


John
 

The +130V rail consumption on a working 7623A is about 50mA. As you have blown a fuse over ten times this rating, I'd suggest having a look around the decoupling caps connected to the +130V rail. On one example I found C1981 on the storage board (0.02uF disc ceramic) had gone s/c. It's safer to disconnect the power connectors on the X amp and storage boards etc. whilst trying to sort PSU problems. As you have so many failures and evidence of past tampering, could you post a photo of your PSU regulator card as it is now?
If the -50V went out of regulation, all the other supplies woudl follow suit and cause mayhem.

John

PS also check VR851: I've seen one go faulty and take the +130V over the top.

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