[TenTec] 9420 Problem

[Christian von Wechmar]

Hi Everyone,

I received a 9420 PSU two days ago. If my information is correct, it stems 
from a Halliburton operation in Gabon. I have been using the matching 
Hercules II amp (with batteries) for more than a year now, and am very 
happy. Had to wait for an opportunity to ship the PSU cheaply, as the usual 
freight charges were too hefty.

Anyway, the 9420 does not work. When plugged into my Herc, and the amp is 
switched on, it (amp) powers up for about three seconds, and then shuts 
down. The meter stays lit however. I tested the PSU while unplugged from the 
amp. When shorting pins 3 and 6 on the 12-pin plug, the same happens. 
Shorting pins 1 and 2 on the 4-pin plug reveals the same issue. 14.5 Volts 
for about 3 seconds, and then nothing. I measured the V at the rectifiers, 
and it appears that they only have power for half a second or so. It is 
apparently long enough to charge the large caps with 14+V.

It traveled by air from Gabon to London to Cape Town, and had two bent 
heat-sink fins. It definitely got bashed along the way, or in its previous 
life. I opened it, cleaned it, inspected it closely, but cannot find any 
obvious problem.

I'll order the manual from TT on Monday, but experience has shown that it 
will take about 3 weeks to arrive here in ZS. It would be nice to use the 
PSU before then. Anyone have an idea/solution/recommendation for me to try 
in the meanwhile?

TU ES 73
Chris ZS1DX