Problems with IBM 5150 Power

I recently acquired a 5150. It is a 16-64k with two drives and color. I have not been able to boot it up yet. I cleaned the inside, and made sure everything was well connected. When I flick the power on, the CPU fan goes, and nothing else. There is power coming out of the motherboard and drive connectors, but there is nothing at the ISA slot. No beeps or anything. I tested the power supply with a modern CD drive. It worked. I removed the motherboard and inspected it for obviously bad components and scorch marks. I then opened the power supply. It was pretty clean, except for the hornet's nest inside. I haven't yet removed that board, but plan to soon. The fuse is intact. Can anyone suggest what to do next? I have PDFs of the Hardware Maintaince manual and the technical service manual. Thanks Joe