Table Saw Help Needed

Table Saw Help Needed · 09-03-2009, 06:50 PM

Ok, I'll admit that I am not extremely mechanically inclined, nor know much about electricity other than the very basics, so I'm stumped and need some help.

Today I worked on my Craftsman (I know many call it by something similar) table saw to set the blade at exactly 90 degrees to the table. The set screws to allow for this could not be freed up while on my back, so I turned the saw upside down, allowing me to easily reach the set screws. I broke them free, and then set the saw back up on it's legs and proceeded to set the blade up properly.

All done, I plug er up, throw the switch, and nothing!

Yes, I have power. Plugging in a hand drill on the outlet proves that.

I've ohm'd out the power cord and it's good. The reset switch shows continuity across both contacts, and shorting them together gets no result.

Next I ohm'd the power switch and get no response, so I assumed the switch may have gone bad, but shorting the switch also results in nothing
happening.

Is it likely the motor has failed bcause I turned the saw upside down? This saw worked perfectly yesterday with no hint of a problem. And, if the motor has gone out, why would I get no continuity across the power switch contacts when I flip it to the "on" position.

Any ideas would be appreciated. Even more so would be the eyes and mind of someone who understands this stuff better than I. I'll even bring the saw with me to someone, (not this weekend because of the holiday) if it means getting this figured out.

Any feedback is welcome.

Jim

Sealeveler · 09-03-2009, 06:57 PM

Some saws have a switch that will not engauge upside down.Check the switch for dust not letting it reset.Tony

JRD · 09-03-2009, 07:07 PM

Tony,

Thanks for the idea, but I sat the saw back rightside up after setting the blade. That's when I first tried it and got nothing.

Jim

Mike Davis · 09-03-2009, 07:10 PM

So, you have power to the switch but not past the switch?

Skymaster · 09-03-2009, 07:11 PM

check the reset switch on the motor,may have tripped.

Phil S · 09-03-2009, 07:14 PM

If you have access to compressed air try blowing the switch out and while you are in there blow the motor out too. Good Luck

JRD · 09-03-2009, 07:45 PM

Mike,

It appears I have nothing at the switch. I ohm'd it out. No continuity between the two poles on the back of the switch with the switch on or off. I pulled the lugs off the switch and shorted them, then plugged the saw in, essentially bypassing the switch but still had no response.

Jim

Sully · 09-03-2009, 08:24 PM

Pull the belt off the motor. You do not need the blade running when doing diagnostics.

I keep a jumper cord on hand for exactly these types of scenarios. Take a short extension cord and cut off the female end. Attach some alligator clips to all three wires.

Then pull the cover off the motor and hook this jumper up to the motor. Remember ground is first to make, last to break. Then plug the male end of this cord into a power strip that is in the off position. Plug the power strip into the wall. Can't stress this enough: do not put power on the cord until you have already connected it to the motor. Cut the power strip on.

1) If the motor doesn't come on, you have isolated at least one problem to the motor itself. Possible problems:

*It could be dust in the motor--which is very likely given what you have described. Blow it out real well. You may have to pull it apart and blow out the internals. Also, when you have the cover off, check all the connections. It could be that when you flipped it over, you loosened a wire somewhere.

*Is this a capacitor start motor? Does it hum when you put power to it? The run and/or start capacitors could be bad. Before replacing them, see if you can spin it by hand with power on it, and does it continue to run?

*Check the reset switch.

2) If the motor runs fine in step one above, then you do not have power coming to the motor from the switch and/or plug. Cut off the power strip. Unplug it from the wall and move your jumper to the motor side of the switch. Repeat the same test. If the motor runs, either the switch is not closing or the feed line is bad.

3) Cut off power strip, unplug and hook jumper to feed side of switch. Repeat same test. If motor runs, then the feed line is bad. If the motor doesn't run, then the switch is not closing.

J

Sully · 09-03-2009, 08:28 PM

Originally Posted by JRD

Mike,

It appears I have nothing at the switch. I ohm'd it out. No continuity between the two poles on the back of the switch with the switch on or off. I pulled the lugs off the switch and shorted them, then plugged the saw in, essentially bypassing the switch but still had no response.

Jim

Mike was asking if you had checked the voltage at the switch. What does the voltage read coming into the switch? And what does it read going out of the switch?
J

Partman · 09-03-2009, 09:16 PM

My Craftsman saw has a gravity switch. After I turn it upside down then back up right I have to bounce the saw up and down a few times to get it to run.

Danny

JRD · 09-04-2009, 05:52 AM

Danny,

Thanks for the information.

My next day off I'll bounce it a bit and see if that works.

Jim

DaveD · 09-04-2009, 01:13 PM

I've seen saws where there is a single receptacle buried under the saw base somewhere where the motor actually plugs in (after the switch). Is yours built like this?

Are you comfortable troubleshooting electrical problems? The reason I ask is you said the switch looked bad (no continuity) yet when you bypassed it the motor still didn't spin. That implies two separate problems. Quite possible but it would surprise me if that is the case.

JRD · 09-08-2009, 08:49 PM

I can't believe it, but I fixed the dang thing.

It turns out the problem was a bad switch. After getting to the heart of the problem I figured, what the heck it's already broken, so I took the switch apart, cleaned it, and Ba Bing. It's working again.

What a relief!

Jim

froglips · 09-08-2009, 09:45 PM

Congrats!

I sure do love the feeling of fixing a busted tool like this. Enjoy!

Jim