|
The first step is to check the VS and VA voltages from the power supply to the sustains. Samsungs usually have marked test points on the power supply. If one or both are missing, do a resistance check to ground on those two lines - they should be essentially open. If you get a low ohm (1-2 ohm) short to ground, disconnect the Y main. If the short goes away, you've got shorted mosfets or igbts on the sustain, and possibly bad buffers as well. If the short remains, do the same with the X main.
There's more, but start there.
John
|