Orbital wiring....

[mwoolfso]

I just experienced a jaw-dropping moment reading this thread.

[dustthisnsx]

alright, well I didn't get electricuted nor did a get any juice..

GFI for safety



wiring to match the awesome sketch





but nothing when trigger is slightly or fully depressed. (checked continuty and all is good in the switch)


Here's where the black wire connects inside


And here's where the black/red connect


also took a look around inside and all looked normal

[tuscarora dave]

I would check for continuity between a few different points while the machine is apart. I don't mean to be insulting by suggesting this but, you have ohmed out the cord right?

To rule out a shorted armature, set your multi-meter to continuity and go between the shaft where the bearing presses on, to the copper segments of the commutator where the brushes ride on it. The windings and commutator should be insulated from the shaft so if you get continuity between the 2 there is likely a dead short in the armature. However, I'd think that would trip the GFCI receptacle.

Also, check for continuity between any one of the segments of the commutator to the very next segment. There should be continuity there. If not, there is an open in the windings however this is very unlikely but worth checking out.

I'd check for continuity between the wires where they go into the switch and the brushes themselves. If you get no continuity between them, I'd say there is an open in the circuit somewhere and would be looking for a burned off brush lead or an open thermal overload switch somewhere. I am not too sure if there is one there or not, I've been looking at that device with the rivet in it where the red and spaded black wire meet at the motor, thinking/wondering if that's not a thermal overload switch or fuseable link that might be open.

Sometimes the lead on these carbon brushes gets really hot and melts down or comes out of the back of the brush all together. Have you inspected these parts yet?

[megacabcummins]

You know how many drill purchases you would have saved me over the years lol... Only one I still have that works is my DeWalt corded, that drill rocks.... Great write up

[dustthisnsx]

I would check for continuity between a few different points while the machine is apart. I don't mean to be insulting by suggesting this but, you have ohmed out the cord right?

To rule out a shorted armature, set your multi-meter to continuity and go between the shaft where the bearing presses on, to the copper segments of the commutator where the brushes ride on it. The windings and commutator should be insulated from the shaft so if you get continuity between the 2 there is likely a dead short in the armature. However, I'd think that would trip the GFCI receptacle.

Also, check for continuity between any one of the segments of the commutator to the very next segment. There should be continuity there. If not, there is an open in the windings however this is very unlikely but worth checking out.

I'd check for continuity between the wires where they go into the switch and the brushes themselves. If you get no continuity between them, I'd say there is an open in the circuit somewhere and would be looking for a burned off brush lead or an open thermal overload switch somewhere. I am not too sure if there is one there or not, I've been looking at that device with the rivet in it where the red and spaded black wire meet at the motor, thinking/wondering if that's not a thermal overload switch or fuseable link that might be open.

Sometimes the lead on these carbon brushes gets really hot and melts down or comes out of the back of the brush all together. Have you inspected these parts yet?

Thanks again for the detailed response I haven't ohm'd the cord but did test for continuity and swapped it with a know good unit. I was thinking the same thing about that riveted piece... going to take a closer look at it. I'm currently out of the area but I'll look it over again and take the multi meter to it when I return. Oh and I have checked the lead on the carbon brushes and all was well there.

thanks again and I'll post my results

[dustthisnsx]

I would check for continuity between a few different points while the machine is apart. I don't mean to be insulting by suggesting this but, you have ohmed out the cord right?

To rule out a shorted armature, set your multi-meter to continuity and go between the shaft where the bearing presses on, to the copper segments of the commutator where the brushes ride on it. The windings and commutator should be insulated from the shaft so if you get continuity between the 2 there is likely a dead short in the armature. However, I'd think that would trip the GFCI receptacle.

Also, check for continuity between any one of the segments of the commutator to the very next segment. There should be continuity there. If not, there is an open in the windings however this is very unlikely but worth checking out.

I'd check for continuity between the wires where they go into the switch and the brushes themselves. If you get no continuity between them, I'd say there is an open in the circuit somewhere and would be looking for a burned off brush lead or an open thermal overload switch somewhere. I am not too sure if there is one there or not, I've been looking at that device with the rivet in it where the red and spaded black wire meet at the motor, thinking/wondering if that's not a thermal overload switch or fuseable link that might be open.

Sometimes the lead on these carbon brushes gets really hot and melts down or comes out of the back of the brush all together. Have you inspected these parts yet?

alright, back at it again at 12:00 because I can't sleep!

- Cord ohmed out at 0.00
- No continuity between the shaft where the bearing presses on, to the copper segments of the commutator where the brushes ride on it.
- No continuity between the windings,commutator and shaft.
- Continuity between any one of the segments of the commutator to the very next segment.
- NO Continuity between the wires where they go into the switch and the brushes themselves
- Pulled a part number off the device with the rivet in it where the red and spaded black wire meet at the motor. Turns out it's a simiconductor! (T1013MH A Tao9322)
Tested for continuity and got nothing, so off to the local hole-in-the-wall electronics joint for a fresh one.



Another member was kind enough take photos from his identical unit for the wiring layout. THANKS!!! I have included it for future reference>>>

[shinysideup]

Dave gave you a great explanation, but if you are still in the dark (and have some time) grab your Snap-On man and have him get the wiring diagram.

My thoughts: That buffer looks familiar, but for life of me, I can't remember who/what the real manufacture is. I'm thinking DeWalt.

Bill

Hi Bill,
The model of the polisher you are thinking of is the Black & Decker 6940 TYPE 100.
Doug

[tuscarora dave]

Pulled a part number off the device with the rivet in it where the red and spaded black wire meet at the motor. Turns out it's a simiconductor! (T1013MH A Tao9322)
Tested for continuity and got nothing, so off to the local hole-in-the-wall electronics joint for a fresh one.

Nice, Please post back if that was the problem.

Another member was kind enough take photos from his identical unit for the wiring layout. THANKS!!! I have included it for future reference>>>

That's the great thing about the members here, such a willingness to lend a hand.

[dustthisnsx]

Nice, Please post back if that was the problem.


That's the great thing about the members here, such a willingness to lend a hand.

Hey Guys,

Sorry for the delay but it took a while to track this part down. However with some help from a little electronics shop we were able to find the proper cross reference part (NTE 5637). Which I later located at FRYS I just finished sodering it in, plugged it in and squeezed the trigger and IT'S ALIVE!!! and just about jumped out of my hands from the torque! Just wanted to thank everyone on here and hope this can help others in the future.

Final wiring pics to come once I can verify the variable speed portion is working... to late and don't want to wake everyone...

[tuscarora dave]

I just finished sodering it in, plugged it in and squeezed the trigger and IT'S ALIVE!!!.

Awesome!!! I was guessing as well as you but I guess they were somewhat educated guesses. Glad you got the problem figured out. Always happy to lend a hand. Thanks for posting back your findings/success.