Ok so Im tryin to fix my bosch sds rotor hammer, you know the big ones with the splined drill bits. Im no tool repair expert so pardon my lack of technical terms. So when you pull the trigger its makes the hum, buzz noise it would normally make but the motor does nothing. Upon opening it up there appears to be a rectifier that is the next thing in the circuit after the trigger switch. It looks just like a regulator rectifier on a motorcycle thats the only reason Im guessing thats what it is, but hey maybe its something totally different. When testing resistance between the supply and the send one side has 0 and one is almost 4 ohms, if it is actually a rectifier that would normally mean its bad. So what Im getting at is would a power tool motor be a DC motor? Arnt most or all electric motors? Should each leg of a rectifier have the same resistance?