[1000mp] 1000MP Power Supply Problem

[9m6xro at amsat.org]

Hi Marcus / PP5MS

Thanks for your help and your experience with the P/S problem. I used
the P/S circuit diagram available at :

http://www.va3cr.net/manuals/1000MPservicemanual.htm

I think you changed C38 (10uF/50v) to fix the problem. 

Unfortunately it did not work for me. After I changed C38 the output
voltage came up to about 12v DC for a few moments but it was very
unstable and
then slowly dropped back to around 6-7 volts so the fault on my P/S is
still there. I also changed out C32, C33 and C34 (all 2200uF/25v) - no
difference.

One other piece of info on the fault. I rewired the on/off switch on the
FT-1000MP and connected an external 13.5v DC supply. When I switched the
FT-1000MP "on" it tripped the external power supply on overload. In the
FT-1000MP I then disconnected the red wire (DC +) from the A/C P/S which
goes to J9002 on the Reg-Unit PCB in the FT-1000MP - after I
disconnected the red wire the external A/C P/S did not trip any more.
Makes me think a component is shorting/leaking around the output circuit
side of the A/C P/S.

Still got the soldering iron on so any more ideas from out there are
welcome!

73 - John - 9M6XRO