[Amps] HF-2500M Control Board

[Steve London]

I am trying to troubleshoot a HF-2500M for a friend. After being 
abandoned by the previous owner for many years, my friend fired it up 
about 3 weeks ago. All was well until the big bang and flash. It was 
just sitting there, idling at the time. The bang/flash seemed to be 
coming from the control board.

Both of the fuses on the control board were blown. Nothing obvious, 
looking at the control board. Everything in the HV PS area (under the RF 
deck, of all places) looks fine. The control board schematic has me very 
confused. Does anyone understand the circuit around the TIP2955, and the 
relation to those fuses ? Anyone care to guess what the big bang was ?


Thanks and 73,
Steve, N2IC