[Amps] Alpha 87A

[Jiri Culak]

Hi guys,

 

ALPHA 87A 

Problem - 

Turn apm on, leave it heat up and already IP meter is going up and down. I
suspected just LED board, but nothing wrong there. When AMP goes into op.
mode

IP goes between 0.1 - 1.0A on the meter which adds it to total. So if I put
20W drive in and get 250mA of IP on real. LED meter shows 1250mA and IP
start to flash and 3sec later amp trips over. Emailed alpha service and got
email back bit later that it might be connectors. I tried that, still
exactly same. Looking on the board as don't have schematic, there is OP AMP
which suppose to sense voltage across resistor in plate circuit. All
metering for IP is done probably on PSU board. 

Any ideas???

 

Thanks,

 

Jiri M0ITY / OK2IT