The fuses are on the pcb's in the power supply compartment in the cpu unit.
If you look through the service manuals and docs, you can see that there are kind of 3 power supplies in there:
5V, 12V and a +/-16V which also has a 48V supply that's only used for phantom power.
As far as I can see, the parts you mention gets their power through the brain board, and the brain board gets power from all three (5v,12, +/-16v).
I would check those fuses first. Then check carefully check the voltage on the pins of the brainboard connector on the power distribution board inside the desk (the pcb that has the BFC on it).
You can see the schematics here:
http://www.sonido-7.com/d8b/files/d8bservice/Block.pdf(page 3)
and:
http://www.sonido-7.com/d8b/files/d8bservice/111b.pdf