20 Volt Circular Saw

[Butch5]

Hello,

 

I've got a Dewalt 20 volt circular saw that shuts off after a few seconds. When I squeeze the trigger the saw comes on runs for a few seconds then shuts off and the brake engages. If I keep turning it on over and over eventually it will run normal. The problem seems to be when I first start using it each day. Any ideas? The nearest Dewalt service center is about 60 miles away so if its just some part I can replace that would be easier. Thanks in advance for any help.

 

Butch

[Framer joe]

Trigger or loose batteries?

[Butch5]

On 12/5/2019 at 7:25 PM, Framer joe said:

Trigger or loose batteries?

I don't think it's either of those. I've tried the battery and it doesn't effect anything, The trigger seems sound. It does it for a while and then stops. It seems to me that there may be an electronic part that is turning off the saw.

[Kevin99]

I have the same problem. Mine does not ever work properly. I pull the trigger and about two seconds later it turns off. I pull the trigger again and the same thing happens. Batteries are good. Trigger doesn’t feel loose or anything out of the ordinary.

[glass]

Throw in garbage buy makita. Problem solved. 

[HarleyAnne]

On 6/16/2022 at 3:59 AM, glass said:

Throw in garbage buy makita. Problem solved. 

 Then see that the Makita is even worse and throw that in garbage and buy Festool.

 

Getting back to the problem, sounds like an electronics fault. Capacitors in particular often misbehave when they are stone cold. Sounds to me like you need to replace the electronics.

[ruggles14]

I bought one and exchanged it the same day for this same reason. Now the 2nd one is doing it too. 

[Seraphus04]

For Dewalt cordless brushless saws

 

Two reasons for this:

 

1: a bearing or gears are seizing up. Keeping them clear if dust and regreasing the armature to blade gear housing and replacing bad bearings is required. 
 

 

 

2: If all you get is a click and squeal then a flashing light it’s going to be expensive. 
 

It’s the electronics package on the field housing. One of the MOSfets has failed. Very fiddly job and a nightmare on the fingers 

 

about 112 quid currently to buy replacement parts if you scour the web. 

 

buy a different model or a second hand one with a larger motor ie 54v as it’s not coping with the load requirement 
 

I tend to find this happens due to blade jam or similar overloading ie trying to cut several sheets of OSB together. 
 

if you have heavy jobs use corded 110/240 tools. Cordless tools are not invincible and very very expensive 

 

 

 

[yakimon]

In my dcs573b saw I replaced the MOSFETs with irfs7434-7p. After the replacement I also used 704 silicone rubber glue to seal the board against dust and moisture.