Hi, I have had same problem few years ago and on that time some leads(white ones) which goes to the field coil was disconnected.They could disconnect when use often the hammer(impact) function at the time drilling.
At the moment I have much serious problem with drilling machine-it doesn´t works at all. I doubt supression condensator is broken.
I have been very satisfied because the Bosch CSB 700-2RE it can be repaired and I have used that over 20 years with that time only two outages.
See parts: www.mtmc.co.uk
Bosch CSB 700-2RE / 0603166703/220V
Arto, November 2009
If the drill comes to life when you twist the mains flex, then there is a split wire conductor inside.....not uncommon and the fault is usually within 6" of the flex ends.