Okay, so I got a a circular saw from the family for Christmas for my burgeoning woodworking hobby, and I've been using it a light amount. It went out the other day while cutting some 1x4. I had a little kicking while sawing through, but not too bad. Suddenly, the saw whirs down and dies. I think the battery is dead, so I switch. No good. I test with my drill, the batteries are both fine.

I've disassembled it fully and put it back together, verifying that there's no blockages, I can manually turn the spindle. Additionally, I've tested the circuit, and there's the ~18v getting from the battery to the spade connectors on the motor, but when I pull the trigger nothing happens. No sound, no motion, nothing.

The only thing in the saw I couldn't identify is some kind of square plate that rests abutting the motor housing. My suspicion is that it's a temperature sensor?

Anyone got suggestions to figure out what I need to do? It's a DCS391 model circular saw.

  • 2
    You got it for Christmas (2015, presumably?) - warranty repair. Of course, you may have voided that via disassembly...???
    – Ecnerwal
    Feb 8, 2016 at 3:24
  • Warranty repair-or-exchange would indeedbe the right answer. Given@Ecnerwal's observation, I'd first try returning it go the store; they're less likely to notice tampering, and more likely to just give you a new unit off the shelf rather than a refurb.
    – keshlam
    Feb 8, 2016 at 3:39
  • Stores only replace the first 30 days unless you bought the extended warranty. Mar 2, 2016 at 13:05

2 Answers 2


In general, it is not worth taking apart tools such as a handheld circular saw or drill. There is not much in the way of user-serviceable parts, and doing so may void any warranty you have with the manufacturer.

First, I recommend looking up if there are any "consumable" parts such as fuses which are user-serviceable. This may be a quick and easy fix.

Your next step should be finding an authorized DeWalt service center that has the specialized tools, parts, and training to repair the tool. The major tool companies tend to have company-owned or authorized third-party repair centers in major metropolitan centers in the U.S. at the very least. They can inspect the tool and tell you if repair makes sense: it may cost more to repair the tool than to replace it. Being this new, however, it is likely covered by a factory warranty that will cover a significant portion of the cost.


Many electric tools have a 'thermal cutoff' . This is like a fuse in the line of the stator. You used to be able to buy them and swap by clipping out the old one and crimping in a new one. - - Look at this article for more info < https://en.wikipedia.org/wiki/Thermal_cutoff>

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.