I am trying to find an wiring diagram for a tile saw mk-660

get the new switch 1st,i have gotten them at orchard supply hardware,for mk 101 before,if your switch is broken in the on possition,you can leave it be for now and use a electrical surge outlet you probably have your tv pluged into,they have a on/off reset switch on them and you can use that to get you by for now or a foot pedal sold at tile stores for tile saws,good luck

the problem is probably the slide cart you set tile on to push it into the blade,on the right side theres a roller you can adjust the the height of the tray,or look at the very bottom of the cutting arm,left hand side,on the outside,where its painted red, theres 2 bolts that hold the cutting arm to the frame of the saw body,try this first, i bet nuts got loose and the cutting arm dropped a tiny bit screwing everything up

The water pump comes to mind.:)
Farmerbear

Just use a rag and grab the blade. Unless the threads are messed up you don't have to hold the arbor still, just the blade.

here is the exploded parts view and parts list.
http://www.mkdiamond.com/pdf/manuals/tile/100/mk100_iso.pdf
You don't really need a wiring diagram. get the switch, swap it out wire for wire... pretty easy.. getting it apart will be the hardest part.

have you checked the brushes ???

there is something wrong inside the saw.

if you are trying different amperage breakers ( trying a 15 AMP breaker and then trying a 20 AMP breaker) or if you are trying all 15 amp breakers try a 20 AMP

check to see if the motor has overload reset button on it (red) usually the water is only pump portion of circuit and can run independent of motor circuit , if not check wiring to motor circuit

On most of the tile project you will need: tile nippers, 1/4", 1/8" and 3/16" spacers, grout sponge, mixing tub, mixer and various trowels.