Was this ever resolved? I have a vetta combo here belonging to a friend (I'm an elec engineer) with a blown AX3 PSU. I've recapped it and the caps will charge up but the voltage control portion seems to be fried. Have replaced the rectifiers, opto - there's a lot of transistors and a current reference comparing the output voltage.
What I'm having difficulty with is that I have no idea what the supply output voltages are supposed to be - the HD PSU schematic is nothing like it. The schematic here is labelled AX3 REV B.