Mackie power amp problem

[drewl]

Got a Mackie 1400i blows the 4- 10A power supply fuses for the +/- 80v supplies.
Think I can try powering it up with the 2n6507 SCR's for protection removed...? or better yet, any schematics for these around?
Thanks.
So far the output devices and associated emitter resistors all seem okay, power trans is good.

Edit: Hey, I have a schematic for this....must have fixed one before!

[MattT]

drewl,
I had one of those blow on me and it turned out to be bad ribbon cables. I found out that it's not that uncommon in these things. HTH and good luck.

[drewl]

I've had ribbon cable problems before, but this thing is blowing all 4 +/-80v supply fuses rather quickly while bringing the voltage up slowly on a variac.

Anyway, standard power supply troubleshooting will commence.