Dewalt 788

[BLULOU]

My 788 won’t start today. I haven’t used it for a couple of months. I checked the fuse it’s ok the brushes ok , ran air in the switch and checked the foot switch ok there as well. Any suggestions?

[OCtoolguy]

Stick a screwdriver in the end of the motor and turn the armature a bit. It's probably just got a sticky spot on it. Make sure your breaker to that outlet didn't trip too. 

[kmmcrafts]

When I had my DeWalt... It didn't like to work in the cold weather... I don't know your location... but mine wouldn't turn on sometimes if it was less than 30F unless I warmed up the motor a little with a heat lamp or something for a couple minutes first.. 

[BLULOU]

I tried the screwdriver for the armature and that didn’t work and also used a portable heater by the machine and still no go thanks for your advice. I’d hate to take it in for service.

[dgman]

More than likely, it’s the switch. The DeWALT switch is not sealed and is prone to dust gumming up the contacts inside the switch. If you are a handy guy, you can check it.  First unplug the saw. Remove the cover that houses the switch. Remove the two wires from the switch and tape them together. Very carefully, plug the saw back in. If it runs, it’s the switch. If it doesn’t run, you will need to get it serviced. If it is the switch, you will either need to replace it, or repair it. If you would like to repair it, let me know, I will walk you through it.

[JTTHECLOCKMAN]

Move the speed control off the spot it is on and work through the speeds and see if that gets it started. Other thing check to see if outlet is powered up. run something else off that outlet just in case you lost a neutral. When you say you checked the fuse did you do it with a meter. I say this because many times you can not see the break. No power is the easiest thing to check on a saw because you always start at the beginning which is the outlet to the plug to the footswitch (take it out of the equation) to the switch, to the motor. Can not go any further. If you are comfortable looking for voltage and taking the switch apart then you should have no problem. Motors just don't stop working. Make sure the brushes are making good contact with commutator. May have to stretch the springs on them to get more tension. 

Edited January 22, 2020 by JTTHECLOCKMAN

[BLULOU]

Thanks everyone, I taped the contacts to the switch and still no power. I’ll buy fuses and see what happens.

[OCtoolguy]

6 hours ago, BLULOU said:

Thanks everyone, I taped the contacts to the switch and still no power. I’ll buy fuses and see what happens.

I'd have started at the fuse. 

[JTTHECLOCKMAN]

1 hour ago, octoolguy said:

I'd have started at the fuse. 

ALWAYS ALWAYS start at the outlet. Need to confirm there is power and proper power. 

[OCtoolguy]

1 hour ago, JTTHECLOCKMAN said:

ALWAYS ALWAYS start at the outlet. Need to confirm there is power and proper power. 

Yeah, you're right JT. I was "assuming" that their was power to the saw. THEN, the fuse.

 

[Scrappile]

I would check the fuse with an Ohm meter before going out and buying a new one....

[JTTHECLOCKMAN]

2 hours ago, octoolguy said:

Yeah, you're right JT. I was "assuming" that their was power to the saw. THEN, the fuse.

 

Never assume anything as I said there could be power but may have lost a neutral and that can be the problem. Unless you know how to look for these things they can elude someone. Yes the fuse is next and needs to be checked with a meter. Those things can look good but really are burnt on the very ends and tough to see. I gave the direction of what the procedure is to get to the motor. As I said motors do not just burn out. I hope the OP comes back with their findings. 

[BLULOU]

I went to the hardware store and bought a fuse and now I’m back scrolling thanks everyone for their interest and feedback. The fuse looked good but it just goes to show never assume.

[kmmcrafts]

Glad to hear you got it up and running...

Funny story but one of my friends relatives computer stopped working... They called tech support and first question was... is it plugged in.. well of coarse it's plugged in.. they had it plugged into a surge protection thing... long story so i'll shorten it up a lot... NOBODY CHECKED to see that the surge protector was plugged in,  " Yes sir.. computer is plugged into the surge protector...looking at it right now.. LOL... "   

[OCtoolguy]

6 hours ago, kmmcrafts said:

Glad to hear you got it up and running...

Funny story but one of my friends relatives computer stopped working... They called tech support and first question was... is it plugged in.. well of coarse it's plugged in.. they had it plugged into a surge protection thing... long story so i'll shorten it up a lot... NOBODY CHECKED to see that the surge protector was plugged in,  " Yes sir.. computer is plugged into the surge protector...looking at it right now.. LOL... "   

I had something like that happen. My outlet strip was down behind my desk and one of my cats stepped on it and turned it off. It was the last thing I checked. Lesson learned. Always look for the easy stuff first!

[Puzzleguy]

im glad when a problem is easily solved - i have had simalar situations with other saws -

So ive learned to always unplug my machine if im going away for a few days or not going to use the saw for a while .

I had a lightening strike a few years ago -and i though my saw was toast -luckily it was just a fuse . and the fuse actually looked ok.

I learned as well about having a few extra fuses ( the old glass type ) they can be hard to find -

 

Edited January 24, 2020 by Puzzleguy

[kmmcrafts]

7 minutes ago, Puzzleguy said:

im glad when a problem is easily solved - i have had simalar situations with other saws -

So ive learned to always unplug my machine if im going away for a few days or not going to use the saw for a while .

I had a lightening strike a few years ago -and i though my saw was toast -luckily it was just a fuse . and the fuse actually looked ok.

 

During any lighting type storms etc.. I usually hit the main breaker switch off in my electric panel... I have way too many saws , sanders, lasers CNC , dust collection, air compressor ect. etc  to go around unplugging... I did the unplugging thing a few times.. and some tools I may not use but once a month or so.. and forget to plug one of them back in... then it throws me into panic mode when something isn't working.. only to find I never plugged it back in... This way.. everything in the shop should be good..  I also do this when going on a vacation etc... no chance of someone getting the remote code for the garage doors and getting it open if the power is off...    

Edited January 24, 2020 by kmmcrafts

[Norm Fengstad]

ON my Dewalt , determined switch problem, new switch would need to be ordered so nothing to loose as I waited for delivery I took switch apart cleaned and  bent contact points for a better connection. Very simple set up , taking apart required some careful prying. It works , the new switch came about 3 wks later and has sat in my tool box for about a year and a half.

[kmmcrafts]

11 hours ago, Norm Fengstad said:

ON my Dewalt , determined switch problem, new switch would need to be ordered so nothing to loose as I waited for delivery I took switch apart cleaned and  bent contact points for a better connection. Very simple set up , taking apart required some careful prying. It works , the new switch came about 3 wks later and has sat in my tool box for about a year and a half.

Can't tell you how many power window switches I've fixed in cars by taking them apart and cleaning up the contacts etc..  I've saved a lot of family and friends money doing this... especially when it's the main drivers side switch for all four windows.. because if that one goes out... they all quit.. and that main one can be $200 - 1000 maybe more these days.. 

[meflick]

In a life long ago, I used to do some computer tech support, we always started with the simple basic, is it plugged in - it often wasn’t People would get mad at the basic, simple questions you would run through but more often then not, it was something basic and simple causing their issue.

[JTTHECLOCKMAN]

32 minutes ago, meflick said:

In a life long ago, I used to do some computer tech support, we always started with the simple basic, is it plugged in - it often wasn’t People would get mad at the basic, simple questions you would run through but more often then not, it was something basic and simple causing their issue.

As an electrician, any time i did any troubleshooting for someone the first question I ask is what was the last thing you did before it stopped working. Many times it was something simple. You would not believe how many times the GFCI circuit or outlet was the culprit. Many times some fly by night electrician comes in and taps off the nearest circuit to install an outlet. If it happens to be the one for the outside outlet or garage or bathroom or kitchen outlet it is on a GFCI and those trip very easily and at times just wear out and need to be replaced. Been there done that and seen that. Always start at the beginning of the power source and work back.  

[amazingkevin]

I love this shop talk!!!!