Advice/Suggestions for repairing Apple III power supply

Hi all -- Picked up an Apple III this weekend in non-working condition, and I suspect the power supply is at fault. Symptoms are: On power up, a rapid clicking noise is emitted from the power supply (maybe 4Hz or so), and the power LED on the system's motherboard pulses at the same rate. Obviously I haven't run it for more than a few seconds like this :). There are no obviously bad parts (burned parts, swelled/leaking capacitors, etc...) that I can see. I'm mostly a software guy but I'm trying to get more into hardware so that I can better maintain my collection as more stuff starts to break down :). I'd like to make an attempt to fix this but I'm unsure where to start. I have found schematics at: http://www.1000bit.net/SUPPORT/SCHEMA/a3/050-0057-a.jpg. If anyone has any advice, I'd be most appreciative. Thanks in advance! - Josh