Mark, I only have some schematics cuts - digital cam photos of a2340sx machine that SteveM sent me while ago. It's different machine but it may be similar in many ways .
From what you are describing my guess would be that your machine have lost +VDC supply from Power Supply to all amplifiers, this supply also is "firing up" relays on Bias board (there rec/simul/noramal switches are also involved).
I've made photos of the prints I have here and am attaching couple of cuts here, see the picture.
There you see main power supply transformer. Look in the area that I've selected with Red border. What I would do - I'd check the voltage as shown, I don't know for sure what +VDC should be there exactly, but I'd guess it may be +20VDC, maybe more, but you gotta have some positive voltage there of that 'range'.
If you do not have +VDC there, then the voltage regulating circuit's components need to be checked. I would not think that the transformer's section is bad in your situation...
Now if you have +VDC there just fine, then you'd want to check the connectors and leads from power supply to the amp boards and check +VDC on the boards. You need to check both +VDC and Ground Wires and connections!!!!
I am also attaching PSU transformer section as indicated "CANADA". I see there are bunch of fuses there on the secondary from the transformer. So maybe your machine has those fuses there, then you sure simply need to check them out.
Also, I assume that you have some knowledge/experience with repairing electronics, using volmeter etc., and I assume that you have an idea about safety issue and how to work on powered-up equipment without killing yourself or setting the house on fire. Saying it just in case, as it never hurts to mention to someone you talk to for the first time
here are the pics: