My 1200W router is not functioning properly. If it wasn't that they
look perfectly OK I would say that it was brush problem ie erratic
power, so I'm going to have to come back down the chain. Switch is OK
so it's something else; I'm going to assume it's the electronics in
between that is guilty.

The box has discrete components so I'm may be able to find what might
be no more than a dry joint, but it would help if I didn't have to
reverse engineer the circuit Does anybody have a reference to a
typical universal motor speed control circuit? Is it likely to be
phase or PWM control ?

Thanks
Rob