I have an InFocus projection unit with a bad power suppky. I have fan action, and logic board action, ( 5v, 12v, 8.5v, -8.5v, but no 28 - 60VDC)
I assume that the 28 - 60VDC is the bulb voltage since I have no lamp lighting. Is there a particular component that I should be checking? Anyone have schematics for the following?

NMB power supply SP1621
aka
IFS p/n 520-0069-04

Thanks for your help in advance.
I have access to soldering tools and multimeters.
Jeff