I had the same problem with my 545A, and it turned out
to be a tin whisker thing. Scrub both the GPIB card, and
the main controller card with a brush, and then blow them
off with compressed air. Try to get the air close to each
chip and socket, and blow from all angles. Plug the cards
back in, and I think you will be in for a pleasant surprise.
-Chuck Harris
Chris Wilson wrote:
Chris,
Put a ohmmeter across any of the capacitors on the GPIB board and see what
the resistance is. Since that kills the unit, I suspect the resistance is
low (?shorted tantalum) or there is a problem with one of the chips that
takes the 5 VDC buss down. Make sure of the polarity of your DMM, + to +
and - to ground.
Alternatively, there is a short on the +5 VDC line at the connector on the
mother board that is 'actuated' by plugging the board in. Measure the
resistance to ground of the +5 VDC buss (power off) with the GPIB board
plugged in and not plugged in.
Joe
Thanks again Joe, checked the tants on the GPIB board and they seem
fine, have put this aside until the rest is AOK. Then I'll pull the
chips one by one and try and isolate the issue. The 5 v bus seems
good with the board in or out, too.
29/11/2012 09:27
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
