[Elecraft] KPA-500 no 478 - shut down when switched from stand-by to operate

[Bernd Länger]

Hi,

I bought a kit in October last year and only assembled it recently.
Assembly procedure is straight forward as described in manual.

The first thing I noticed was that the amp was not always amplifying 
properly while the transceiver was in transmit mode. '*' sign was always 
visible when transmitting, but it just didn't generate constant output. 
At that time I put it aside for a while. I just got it back on my desk 
again today to have a look at it.

Switching it on was ok, but when I switched it to 'operate' from 
'stand-by', the amp immediately blacked out (first time this has 
happened). The transceiver was on stand-by at that time, just pushed the 
operate/stand-by button and it happened. Fuses are still ok, so 
something else must have happened.

Would anybody have an idea where to start looking for the fault?
Thanks

-- 73 Bernd VK2IA