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Repair information and guides for grinders, including angle grinders.

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Angle Grinder Black & Decker stop suddenly

Today i tried to polish my car using my Grinder, but after a few minutes of working, it stoped.

I can open it, but i do not know what are its basic parts.

If somebody point me where and what are the most possible parts to failure, it will be nice.

It seems to me, that the damage happened because of the resistance applied on to the devise, while i push it on the surface of the car.

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Hi @dorosk ,

What is the model number of the grinder?

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Hello.

It is a BLACK&DECKER 701Watt.

Model CD105 - PRGR Type 02.

10000RPM.

230V, 50Hz.

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I have a Black & Decker grinder a g750 and the trigger is bad on it I've already checked it out but it has some type of a capacitor or a fuse or something also on the trigger I don't know what that is or that it could possibly be bad instead of the switch what is that on that trigger

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Hi @dorosk,

If you have a DMM (digital multimeter) use its Ohmmeter function to prove that each wire in the power cord has continuity from end to end, from the plug to the connection in the grinder, just in case it is a broken wire in the cord.

If the cord is OK it may be the trigger switch (supplier example only) or perhaps the carbon brushes to the motor.

Here’s a parts list that shows all the parts that may help. The reason I linked a different supplier for the trigger switch is that this supplier shows that it is no longer available, but if you search for the part number i.e. 569159-00 you will find other suppliers that have stock.

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Thanks for your detailed answer.

Before i will disassemble the grinder, i want to ask if there is a way to check the trigger switch. I have a multimeter.

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@dorosk

I don't know the device but looking at the image I posted it appears to have only two contacts so maybe if you connect your Ohmmeter across the two terminals and take a reading and then press and hold the trigger and then take another reading it may tell you whether there is any change etc. Of course you have to disassemble it first to do this

It may be that it is a simple on/off or even some sort of potentiometer type of switch i.e. resistance changes the further you press the trigger from off to full on. Worst case is that it is electronic so hopefully if that is the case you won't get a reading at all because it has failed.

The other way is maybe to connect your Ohmmeter across the two power pins of the power cord (unplugged from wall outlet of course ;-) and then press the trigger and check if there is a reading or not but I'm not sure if this will work as I can't find the wiring diagram and the switch may not be direct in line with the power supply so to speak

This is just what I would try.

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OK, I fixed it !

Kevin Sargent and jayeff thanks forhelp. Before read your comments, i did not know the parts of a Grinder, and without your help i could not fix it.

When i dissasemble the trigger switch i looked for a moving part. There was one, but its movement did not affect anything. There was two pairs of terminals (down and up) but seperated and the movement of the switch did not affect either. Because this was not normal, i suspect that one pair of the contacts must have been stucked somehow. Althought i might damage the switch, i took a tweezers and pulled up the “down” connector, and It came off and came to its physical position, where the two pairs of connectors were touch eachother. (what was happened, really it was that when i pulled up, everything ejected from their position and for several minutes i tried to figure out what part were, in which potition) And when switch change position, connectors seperate from each other. .......CONTINUE IN NEXT COMMENT

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...........What was hapened it was that the plastic was melt and the metal got stuck into the plastik. This was because , i had the trigger switch in the second position (the one that somebody have not to hold it all the time). As i noticed, in this position, the “down” connectors comes down (to the very far position) and touch the plastic. This do not happen in the first position , where you must hold the switch all the time. So in this far position (where touching the plastic), after some minutes the metal connectors were get hot, and melt the plastic.

So to avoide from this happen again, i place a litle piece of Alouminium tape in the area where (in the far position), the connectors touch the plastick. I stuck the Aluminium with silicon, and i hope that it will not move from there, cousing other problems.

Because i cannot see any option (here in comments) to upload some pictures, i will do it as an answer.

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@dorosk

You may have to be careful that the aluminium can carry the current required for the motor.

Over time it may oxidize and create a resistive surface which may become hot and/or prevent the motor from turning due to the increased resistance or the voltage drop (heat) across it.

Given the cost of a replacement switch it may be better in the long term to simply replace the switch.

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Replace the motor brushes. I’ve fixed Many tools that way. I hope the commutator isn’t too bad. Most people don’t know to look at the brushes / commutator arcing on all brush motor tools. If it’s a constant low level blue - all’s good. As yellow then white start appearing and the size of the flashes get bigger - replace brushes. When you get the new set, compare lengths. The longer it’s run with yellow white arcing getting worse, that’s damaging the commutator.

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Thanks for help.

First i want to check the trigger switch (as jayeff pointed out to me). If it is OK i will continue with brushes and commutator.

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