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CS50 Whine...

2014-07-17 by bob@...

Hi


Just servicing a CS50, and it's constantly outputting a whine of about 4120Hz.

Unit came to me a bit battered as the PSU had shaken loose and trashed a few things inside.
PSU PCB had become cracked, so replaced that with a working one purchased from Synthparts.
Recapped the new PCB before I fitted it.

I've done the usual, changed the logic on the KAS board and the S/H board, replaced power decoupling caps throughout etc.

The only difference is that originally it took a minute or so to manifest... now it manifests immediately.

I can see the signal on all power lines.


Any thoughts?


B

 



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