CNC 3040T-DJ Router

Mini CNC Engraving T-D Controller

Hi All
I was running a job - and accidentally set my z level too low and in the middle of the job, the bit hit the bed and snapped.
The strange thing is, the spindle won't stop spinning now. Even when i turn the manual speed control up and down and try to switch off the spindle on the control box. I've tried shutting everything down, including the computer, and rebooting. No help. Tried disconnecting and reconnecting the spindle motor. No help...
Anybody else experience the same issue? What may have gone wrong, and how do i fix it?