Old box fan and 'Lectric Motors 101

Re: Old box fan and 'Lectric Motors 101
IIRC, I used to know a bit about Electric Motors. That was back around 1970, and my memory is poor.
They must be building them to last. I haven't needed to work on one in many years.
But, when it rains, it pours. Now I got 'bout 3 EM's that might need repair.
One is an old K-mart box fan (a Lakewood K-223) that's gave good service for maybe 30 years. I even built a little stand for it ...
So I turn it on hi yesterday and after a few seconds I got a pop and spark out of where the wires enter the motor, and it stops. Today I clean 30 years of crud from the windings etc, reassemble, and test on lo. It runs for 20 secs then does the pop/spark again (and quits). I unplug quickly.
Here's the 'Lectric Motors 101 part. There's windings, brushes, and a rotor inside? Long time ago, it was practical to replace brushes as necessary for some EM's. What do you look for? What can you do/not-do?
It's a shot-in-the-dark, but I'd like to keep the fan going if possible.
I guess this is not a query for folks who pitch/buy- new without thinking about it. Might be a question for a good terminal tinker ...
TIA, Puddin' ******************************************************* *** Puddin' Man Pudding_Man at mail.com *** *******************************************************;
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<< runs for 20 secs then does the pop/spark again (and quits). I unplug quickly. >>
IIRC these are usually shaded pole motors and run on AC only , hence no brushes. Look for some wires with insulation rubbed through and you may find your problem. Leads to the field windings are good suspects, maybe failed solder joints.Persist and you may succeed. Quit and you've failed. That's the cliche' for today. HTH
Joe
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Puddin' Man wrote:

Your PC must be resending these messages on it's own. http://groups.google.com/groups?hl=en&lr=lang_en&ie=UTF-8&c2coff=1&safe=off&selmA0d7bf5.31043578%40news.west.earthlink.net
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Puddin' Man wrote:

point out to the fire marshall that the fan is probably the culprit of the fire....
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