Hi all

Some help on this would be very much appreciated.
I have two Placids in the box, each powering their own Legatos, for the sake or argument lets call them DAC1and DAC2.

DAC2 Works fine (Placid, legato and Buffalo)

I have been having a problem, when the Placid in DAC1 has some fault, in that it turns on ok without the legato connected. When I then switch off, and connect the Legato, switch it back on, two much current is running through it. This initially manifested itself witht he -ve rectifier blowing up. Upgraded rectifiers to bigger ones, and now it just makes a very bad crackling sound when turned on WITH the legato, so i immediately turn off.

I tried the DAC1 Legato with the DAC2 power supply, and that seems to be fine, so the fault is definitely with the DAC1 Placid.

Now, can anyone suggest where in the circuit I should start looking?Is there any transistors that are likely to have failed/shorted that might cause the thing to draw so much current? Its like it pulling far too much current, and when i have had it working briefly all voltages all check out fine. Only seems to be the negative one, so that side mush be where the fault is.

Look forward to some thoughts, someone must have had faults on these before

Thanks!