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Help with bizarre problem

6/17/2003 12:05 PM
drewlHelp with bizarre problem
hi, I have a Peavey Ultra 100w (similiar to 5150) with 120hz coming through the output tranny.amp had a blown screen res. you'd think power supply filter caps right?  
well, I replaced them, here's what's weird....the ac is on the output tranny center tap, or right after diode bridge, well if you disconnect the tranny, the ac goes away. the diodes seem good because they are rectifying the ac.  
i was going to jumper in a new output tranny to see if that's the cause.  
I disconnected all ribbon cables to output tube board (yuch!) and jumpered the B+ and the noise is still there. but only with output tranny connected.  
Tranny ohms out okay, but under voltage....who knows.

 
Replies:
dpcoyle If there is AC after the rectifiers... -- 6/17/2003 1:03 PM
Enzo Check your tranny for shorts betwee... -- 6/18/2003 6:58 AM
Enzo Well here is a tip. It is a hell o... -- 6/19/2003 7:37 AM