bosch compact 450 mixer troubleshooting help

I bought a Bosch compact 450 second hand, opened it up and gave it a good cleaning.

It worked fine but some dough gunk was seeping through the dough cover so I opened it up again last week to clean the inside again but now it doesn't work!!!!!!!! 

The blue light turns on when plugged in but when I turn to any speed, it doesn't engage the motor and the light flashes.

I took off the screws again to check if anything was pinched or caught, put it back together and still not working.

Any ideas?  I love this little mixer and want it back working again:(