i had one that was the same here in uk,it was running but,no sound,did exactly the same as yours and failed at the sound cpu test.i bought a quake board (the small board) and a sound and credit board from usa and i swapped them and it corrected itself,so i doubt its the wiring or psu thats the issue.
the board was working fine till 1 day it decided after being turned on to stick in test mode,its a machine i am waiting to get round to fixing,just ended up with a backlog of machines in front of it,all i managed to do was try different boards and swap the test switch round but,to no avail.
with the big caps that are on the board it makes me wander if its power related but,down to them caps or perhaps a regulator on the board.i will try to get round to setting the boards up on my cab and metering the faulty and the board thats stuck in test mode to see what readings are there.
i do remember that i swapped the chips and there was no change.
looks like both you and me have probs with blasteroids.
i seriously doubt changing the big blue on the power supply will change anything and the psu will be outputting the correct voltages,i tried to swap mine with others i have that do work but,same prob.so i would say its more a prob with the actual board myself,i just cant be 100% until an expert who realy knows comes along.
