angle grinder - intermittent motor troubleshooting

Old 03-25-11, 04:27 AM
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angle grinder - intermittent motor troubleshooting

Greetings! I'm not sure if my question is appropriate to this forum, because I didn't see similar types of questions. Here goes anyway.

I have an almost new 5" Bosch angle grinder whose motor runs intermittently. It was used in extremely dusty conditions. I took the casing off once and blew out as much as I could. Took the motor core out and did the same. This worked for about an hour. A second try has not been successful.

Any hints as to key points to verify or clean? Any other suggestions/hints will be appreciated. I am by no means an electrical wizard so please try to keep layman's to terms and words of few syllables.

By the way I'm virtually certain 'take it back' is not an option since the conditions it was used in almost certainly void the warranty.

Old 03-25-11, 04:46 AM
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I would start first by blowing the motor out using compressed air through the vent holes. But your symptoms are indicative of 1) bad brushes, 2) bad switch or 3) bad cord most likely where it enters the tool. Checking the brushes is pretty straight forward and you don't have to take it apart to check them. The other two will require cracking the safe.
Old 03-27-11, 09:01 PM
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After a good cleaning w/air you could try an electrical contact & parts cleaner aerosol. Clean w/air after spraying and give it plenty of time to dry before plugging it in.

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