Aid Needed in Troubleshooting a Power Designs 3650S Power Supply

[DC912]

I picked up a Power Designs 3650s power supply in decent cosmetic condition, but unknown operating condition.  Turns out it needs some electronic repairs.

The symptoms are:  The DC+ at the output is always about 1/2 of the voltage indicated on the panel meter (in other words, the voltage at the output  is always about 1/2 of the indicated panel meter voltage when increasing from 1 to 36v), and the DC- at the output always hovers near zero.

The current limiiter appears to function. The transformers check out okay.  There are no signs of physical damage or prior repairs inside.  I checked the electrolytics in circuit with an LCR meter and they appear to be okay too.   

The schematic is on the ko4bb site.  Any thoughts on specific components or circuits to check given these symptoms would be appreciated.  Thanks.

[eas]

The 3650S is a floating single output supply. Are you measuring the DC+ to ground, or to DC-?

[electr_peter]

The 3650S is a floating single output supply. Are you measuring the DC+ to ground, or to DC-?

I guess DC912 measured DC voltage to ground, but not between DC+ and DC- terminals. This statement seems to suggest it:

The symptoms are:  The DC+ at the output is always about 1/2 of the voltage indicated on the panel meter (in other words, the voltage at the output  is always about 1/2 of the indicated panel meter voltage when increasing from 1 to 36v), and the DC- at the output always hovers near zero.

Measure voltage between DC+ and DC-. Voltage readings between [DC+ and Ground] or [DC- and Ground] are meaningless as this is a floating supply.

[DC912]

Thanks for the replies.  Yes, I was measuring between ground and DC+/DC- because I presumed, incorrectly, the ground was common.  It never occured to me that this was a floating supply!  Thanks again.  Dave.