18 Jul
2004
18 Jul
'04
7:37 a.m.
Obtain a simple method of reading continuity,
resistance, and voltage,(AC
and DC) - most el-cheapo DVMs fit this spec nicely. Use it to determine
IMHO anyone who works on classic computers must have a multimeter. It is
essential to be able to check PSU voltages, find open-circuit fuses, dead
switches, and the like. Even if you don't want to get into more complex
troubleshooting.
the static and dynamic state(s) of the motor supply
and control circuits.
Is there AC voltage available to the motor circuits? IS there any voltage
At this point I'd be trying to work out why the relay wasn't pulling in.
The AC side is quite possibly fine, the motor only runs with the relay
pulled in (that's what the relay is for!). And the relay is controlled by
low (12V, 5V) voltage logic circuitry. Of course there's mains on the
relay contacts.
I asusme you have the prints. If not, I'll dig out my set.
The usual cautions about working on energized
electro-mechanical devices
apply: professionals, closed course, don't try this At Home,
yada/yada/yada...
I'm no professional, I do this sort of thing at home. Heck, I've worked
on an 11/44 PSU and lived to tell the tale :-)
And it is possible that Professor Duell will grace you with his spot-on
And I can assue you I'm no professor ...
-tony