Thanks. There is indeed a short in the bridge rectifier (KBU606.)You will need to try to isolate whatever components that you can from the incoming power and check them with an ohmmeter. You are looking for a source of low/no resistance. Within my unit, one of the diodes within the bridge rectifier went out and caused a similar issue. It looks like a tall, thin, black block with a hole through it and 4 leads.
Ordered the replacement varistor and bridge rectifier for the IO board and already replaced the op amp on the control pod. I've spent $8.40 so far and I have 5 extra op amps and 3 extra varistors. Not bad.