Pyramid R P S not working properly
 

Good morning,

I went to turn on my PS-50 today and its only producing less than a half volt dc... it did work a few months ago but I did notice that it would make full power. Was a lil over 13.7v rated to produce 15v.

The voltage is somewhat fluctuating several point volts and has ranged from .5v to 1.6v but will go back down. I thought that is might be the voltage potentiometer (knob) as it has little effect... can I bypass it somehow just to see if that was the problem? If so, what value resistor should I use?

Thanks in advance, looking forward to getting this back up and running.

Bump, still having no luck... does anyone have a service manual or schematic? Its a pyramid phase 3 PS-50. Would really like to get this thing going again. thx

This should help.
 

http://userpages.troycable.net/%7Ewj5o/PS-35.jpg
I would check the thermal fuse that is within the mains transformer first, Check there is output on the power transistor collectors and then, if all is OK, check the control IC and Over voltage trip. :)

Look for the IC number and the download the datasheet. Before that, check the voltage after the rectifier, across the filter capacitor.

Gajanan Phadte