I was drilling a hole in the wall with my 1984 vintage Bosch CSB 470-RLE impact drill, when it suddenly gave out. I figured the stone was too hard, increased the power on the potmeter and it worked for a couple of seconds until finally stopping. I didn't smell any 'electrons' or other burning scents.
Now I can't get it to rotate again.
I've watched some youtube instructions for fixing common failure mechanisms, such as failure of the electrical switch as well as expiration of the coal brushes. However, I find a voltage on the commutator as well as on the coal brushes (i.e. electrical contact is sufficient) when I press the electrical switch (i.e. switch not broken). I took out the coal brushes and they are still about ~2 cm or 0.75" long, more than sufficient I would think.
Does anybody have a suggestion on a possible root cause for the motor no longer working?