need information

[hhermans]

from hhermans: Thanks for the invitation to join! I'm
hoping this can be of help to myself and others. I removed the circuit board from my brothers Dewalt DW 788 scroll saw, because the motor
no longer worked. I replaced a few parts includig the potentiometers{variable resistors}. My bro. {meanwhile} put the saw back together.

I needed to see where the AC cord green wire {ground} was attached to the body of the saw AND if the board has another ground wire or is mounted in such a way that it picks up that ground when it is mounted on the saw?

If you have yours apart and can see these answers in front of you, we may be able to help each other! I doubt that any of you have a schematic of the motor control board,but if you do I would really appeciate if you would share it! I am in the process of drawing the schematic as we speak .
Once More THANX for being there! JOE

[Wood Dog]

Welcome hhermans........If anyone knows about scroll saws it is Rick Hutcheson. His web site is
Rick's Scrollsaw if you don't find what you want there maybe you could send him a pm, he is on this forum too as RICK H

[Forester21]

Have you checked on the Dewalt website? They have the owners manual there (or at least they used to)
Welcome!

Theresa

[Rick H]

I do not have the schematic for the Dewalt.

[GrayBeard Phil]

Joe:

Welcome to the forum! I hope you enjoy your visits.

BTW:
Elsewhere I read where someone had a bad motor on their DW 788. Turned out there are two carbon motor brushes on the motor. On some 788's the motor is mounted so the carbon brushes are top (up) and bottom (down) on motor housing. The brush closest to your support table (bottom) can get clogged with saw dust and thus the motor won't run. Used compressed air, if I recall correctly, and normal motor brush maintenance got it working again; don't remember if the owner had to replace both carbon rod brushes.

Phil

[lonepine]

Yes, that was me with the bad motor, I did not find a schematic,but I purchased another circuit board,which was not the problem,it was the motor all the time. As Phil said the carbon dust collected on the bottom brush holder and eventually blew the commutator bar on the motor.
P2 was white in,
P1 was black in,
M+ to motor, black
M- to motor.white
I beleive the ground wire was attached to the housing,and not to the circuit board.
It produces 50VDC to 94VDC.
Hope that helps.
Need anymore specific's,let me know.
Thanks, Bob

[Tinker]

Lonepine, did you have to replace your motor, and if so, where did you find a replacement that didn't cost half the price of a new saw? The motor went out on my 788. I have a bosch motor that will work fine. I will just have to mount it outside of the case and drive the saw with a belt and pully setup , but can still use the speed controls on the saw to vari the motor speed. I would rather use the motor made for it but have a hard time justifying the cost from Dewalt.

[Don McLeod]

If you completed drawing the schematic for the PC board, would you be kind enough to post it here.

Thanks