[Amps] Alpha 89 soft fault

[Robert Pack]

One of my Alpha 89's has been acting strange.
While transmitting, it occasionally has a soft fault......when I toggle the oper/stby switch back to oper, it again works but ends up faulting again at some point.
It SEEMS to work fine at lower power, say up to abut 600w or so.
There are no leds blinking when it faults to tell me what the fault might be.
I have sent a message to Alpha but they are likely closed today so just thought I'd ask here if anyone has had the same problem and a possible fix.

Bob NX5M