Re: Dying GS power supply?

[rubywand@aol.com (RUBYWAND)]

In article <48ub1a$52f@gap.cco.caltech.edu>, nathan@cco.caltech.edu
(Nathan Mates) writes:

>Ok, my GS is acting weird, and I'm trying to figure out why. When I
>hit the switch on my System Saver, the GS sometimes acts like it's not
>plugged in at all-- it just sits there, no beep, no power light, no
>action. I checked the power switch in back, and with my multimeter,
>determined that power was going into the power supply, and out of the
>power supply's connector. When I replaced the power supply after these
>checks, the GS powered up just fine.
>
>   This has happened 2-3 times this week, and the only way to get my
>GS to power up has been to pull out the power supply and put it back
>in. Then the GS works. Next time I power it up, it may not.

    Really, the above are classic Loose Connection symptoms. Next time the
machine doesn't come on, try wiggling wires going to the power supply
connector. You may have a loose wire-to-plug joint or a loose lead
connection on the power supply circuit board.

    The problem could be or a loose power socket connection on the
motherboard. Sometimes the solder around a pin inserted in a circuit board
fractures. This results in intermittant contact which can be hard to spot.
(This problem especially plagues the IIgs RGB monitor.)  The cure is to
re-do the connection with fresh solder.

    You can help isolate the problem by pulling the power plug from the
motherboard and checking voltages on the plug. If the problem appears to
be with the supply, open it and check lead connections to the board.

    If these are okay, a fairly good suspect is the little disk-shaped
globar resistance element (usually near the AC input). Sometimes one of
the leads pops away from the disk element. Since the lead may be just a
gnat's whisker away, it may be moved into contact by jiggling the case or,
even, by temperature changes.  


>I've been wanting a new power supply for a while to get rid of the
>various noises out of my power supply (especially when the mouse is
>clicked), so a IBM PC desktop case may be the solution (such a thing
>would also hold my HD, floptical, etc). Some people have recommended
>Alltech's Tony Diaz for an IBM -> GS power cable, is this still right?
>
    Probably, Tony can fix you up with a PC-to-IIgs plug converter. You
could also just cut off the plugs on both supplies and splice the leads
from the old IIgs plug to the correct PC power supply leads.