Dewalt brushless headache

[Terence Gregory Blake]

Hey, just trolling the electronics geniuses at Sector if anyone has any experience troubleshooting a blown brushless motor controller that is dipped in resin so nothing is accessible.  I would be perfectly happy to jury rig/over ride/MacGyver this thing to work, but I am not knowledgeable about brushless systems.  In this case, the controller accepts either a 120 AC converter that supplies 120 DC or (2) 60V DC Dewalt batteries.  The controller has a substantial scorch and no power output, but I do not even know how to isolate or measure anything.  (Tried to find parts, but all that is sold is a whole motor and controller for nearly the price of the saw.

Thanks in advance to anyone with ideas.

[Chris Meyer]

Got a picture of the board/destruction?  What's the saw model/part number or the board part number?  

It is possible to de-pot boards but it's a ton of work depending on the compound used, often with high power drivers the driver circuitry can fail leading to the MOSFETs blowing up (the burned part) but the less obvious part is swapping the FETs will just yield more destruction because the drivers/protection circuitry is shot.

Chris

On Sun, Jan 11, 2026 at 9:28 PM Terence Gregory Blake <tgbdeve...@gmail.com> wrote:

Hey, just trolling the electronics geniuses at Sector if anyone has any experience troubleshooting a blown brushless motor controller that is dipped in resin so nothing is accessible.  I would be perfectly happy to jury rig/over ride/MacGyver this thing to work, but I am not knowledgeable about brushless systems.  In this case, the controller accepts either a 120 AC converter that supplies 120 DC or (2) 60V DC Dewalt batteries.  The controller has a substantial scorch and no power output, but I do not even know how to isolate or measure anything.  (Tried to find parts, but all that is sold is a whole motor and controller for nearly the price of the saw.

Thanks in advance to anyone with ideas.

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[Terence Gregory Blake]

It was the DHS-790.  Longer parr number is just with batteries and power cord.  No one seems to list a part number for just the controller. Instead you can buy the motor assembly with controller.  But typically over $400.  

Thank you,

Greg

On Jan 11, 2026, at 10:33 PM, Chris Meyer <wate...@gmail.com> wrote:



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[Chris Meyer]

Reverse image search:

https://www.reddit.com/r/Dewalt/comments/1fke0n1/need_help_proceeding_cant_find_this_part_for_sell/

Clever suggestion, you could use an eBike motor controller and your 60V batteries to make it variable speed and running again.

More info here:

https://forums.aeva.asn.au/viewtopic.php?t=7038

The great LLM in the sky digging results out of images is one of the few benefits to unaffordable RAM and non-drinkable water ;-)

Chris

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