Hello. I have a Bosch CSB500RLE, serial no. 0603 147 842 corded hammer drill. It is quite old but is a superb piece of kit. It has just begun to work intermittently. Sometimes it works, sometimes not, sometimes it starts if I shake it or turn it upside down. I have checked the brushes and they look OK, I also cleaned the commutator, though it looked OK. Any suggestions please? Could part of the armature/magnet have burned out - if so it's obviously not worth repairing?
Thank you in advance
John Lund

john, May 2009

I have the same problem. I originally thought the switch was faulty or there was a loose connection in the power cable somewhere. I opened the drill and it looks like it might be the carbon brushes which need replacing. Current seems to be going to them but they seem very worn down compared to a new set I have seen on the Internet.

Bohma, September 2009

Its curious that the drill sometimes behaves itself when shaken or turned....this may indicate a faulty mains cable, the conductors of which may have severed inside the insulation where the cable enters the drill. Next time the drill doesn't work, hold it still on the bench and waggle the cable to see what happens.

John, May 2009