Sparks flying out of my new Bosch SDS drill hammer

[bjorx]

as i was drilling it almost seemed like the machine caught on fire inside or like a small welding arc. it lost power and smelled burnt as well.
the area it came from is where the brushes are. opened it, cleaned,looked and nothing wrong. brushes in excellent condition and Everything rotates fine. put it together and sparks again.
the problem started from one second to another.
My Bosch GBH 2-26 DBR/bulldog extreme(profi) has been used less than 2 hours....

Is the bearings fawlty or something else making the brushes operate somewhat out of place?
Best Regards/ MB

[Job and Knock]

I'd start by looking at the commutator and the brushes again - that's the most likely source of problems. On an almost new tool, though, you shouldn't be having problems like this. I had a Kango saw which went the same way - turned out that one of the windings had shorted (insulation on the windings had broken down, although the motor was absolutely full of Tufnol dust) - that meant the motor was toast. Hope yours is still under warranty

[Job and Knock]

I should have pointed out that it's quite normal for a new tool to spark a bit more as the brushes bed in, but that doesn't take such a long time (an hour or so's use). If you ever see what looks like a solid ring of white sparks around the commutator and smell burning then that's far more serious