I think I broke my PWM speed controller

I found that when I ran the spindle the keyboard of the computer would act unreliably which makes CNC kinda tricky. I figured it was probably EMI from the motor so I tried putting a capacitor across the motor terminals to short the high frequencies (also known as a snubber). However I didn't realise my motor speed control was PWM based, and so it basically shorts all motor drive and the circuit blew. Doh!

It will cost me about £15 in parts to replace most things that could be the problem (not clear what blew).

On the other hand can you guys recommend an alternative affordable DC motor speed controller?

I have also considered just making an alternative mounting bracket and breaking apart an affordable hand router for the AC motor and speed control. Why not??