Re: IBM monitor won't start up - relay keeps tripping

From: Scott M (spamkiller_at_elp.rr.com)
Date: 07/17/04 

Date: Sat, 17 Jul 2004 07:26:06 GMT

Thank you both for your feedback. Upon close inspection of the PCB, I didn't
find any broken solder joints. I couldn't find any obvious short or open
circuits either. I did find a FET that has a D-S short. I removed the FET
and testted it off the board and it still showed a short. If I understand
correctly, a FET transistor is similar to the bipolar as a bipolar should
not have any short between E and C. Therefore, this WOULD indicate that the
FET is fried, correct? I do not understand how a fall would cause that to
happen, but if it's bad, I'll replace it.
I've got a few more to test, but all the other transistors and diodes look
OK as far as my DMM readings go. I'm also doing the best I can to trace the
power supply circuit with the schematic (which has been somehwat elusive so
far).

"Scott M" <spamkiller@elp.rr.com> wrote in message
news:3cpIc.36687$W6.31701@fe2.texas.rr.com...
> I found an IBM monitor model 6547-00N (chassis CM-1317). I cannot get the
> unit to start up. It has a relay that keeps clicking on-and-off but there
is
> NO VIDEO. The monitor appearently suffered from a fall but there are no
> visible cracks in the PCB. The monitor has a feature that causes it to
> de-guass automatically upon power-up and I suspect that the relay that's
> going on and off has something to do with the de-guass routine. Has anyone
> ever seen such a problem? My next step is to try and locate a schematic
for
> this monitor so I can check test-point voltages and begin tracing the
> relay's power supply.
>
>
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