mitre saw

[333rocky333]

Yes I know its only a cheap saw but
I bought it for about 100 pound just for diy use and had my moneys worth, however after not using it for a couple of months I got it out cut one bit of 4 x 2 not really straining it, there was a pop a puff of smoke near the brushes then it stopped and now dont go.
Yet to dismantle it but is there a remote chance of an easy fix, perhaps like the brushes or link lead blown apart.
Few years since I done motors, any like continuity tests i can do to the windings or armature, before i condemn it.
Thanks in advance

 

[conny]

Possible the brushes have worn down to the wire connection and been dragged around the commutator, shorting out more bars than the brush sits across when running.

Take the brushes out and try to see if there is any damage to the comm bars. They may look a bit dark, especially between the bars where the mica is but this may just be carbon dust. If there is no obvious damage try to blow out any dust with a compressed airline, avoiding breathing in the dust!

If you have access to an insulation tester, (commonly known as a 'megger' you could test the insulation by setting it to 500v and checking it has not blown to earth first. If it has then its cheaper to buy a new saw. If not the fit new brushes and give it a try. If it still doesn't work then you have only added the cost of a set of brushes to a replacement saw.
You could test the resistance of each stator, (field), coil to see if you have continuity and they are balanced. To test the armature you would need to strip it down and do a volt drop test across the bars. Not really worth the time and effort though.