Dewalt DW788 blowing fuses - Scroll Saw Woodworking & Crafts Message Board

Don McLeod · 10-02-2008, 01:09 AM

a friend of mine asked me to look at his Dewalt DW788 as it had no speed control and would blow the 3 amp fuse after 10=15 seconds of running.

When first turned on it runs at full speed and the rheostat does not vary the speed, shortly after running it will blow the fuse.

I checked the brushes and also checked the rheostat with a multimeter and it seems to be ok.

I suspect that there is a problem with the printed circuit board, is there someway to test the printed circuit board to see if it is operational.

Has anyone else with this scroll saw had a similar problem and what was the remedy.

Any incite on this problem will be appreciated.

Thanks

Forester21 · 10-02-2008, 03:12 AM

How long has he had this problem? And did it start shortly after a thunderstorm??

Rug Rat · 10-03-2008, 08:20 PM

I have had the same kind of problems. A new saw and with about 15 hours on it when it started. It would either speed up or slow to about 50 strokes per min then blow the fuse. Factory store replaced the electronics and electrical. new board, speed control,fuse holder, on-off switch and 3 days later the same problems so they replaced it with a new saw. Out of the box it did the same thing. The table was also a very unflat casting. I returned it and got most of my money back and purchased an Excaliber EX-21 and it purrs like a kitten with none of the same problems. This episode took me about 2 mos. to work thru with no solution. Good luck

Dragon · 10-04-2008, 03:10 AM

Mine was blowing fuses but it started during a thunderstorm and eventually it blew the motor. The service center honored the guarantee and gave me another saw.
Diane

SNAPPER · 10-06-2008, 09:45 AM

Not sure if the circut boards can be tested. Could be an issue with the windings in the motor.
Dean

Don McLeod · 12-31-2008, 10:23 PM

for the replies.
Its been a while since I had a look at the saw but since my first post I've dismantled it and disconnected the motor and it is still blowing fuses. He had been in the hospital for some time and during that time a severe thunderstorm took place and the house next door lost most of their electical equipment, "phones, tv, modems ,routers etc. so it is possible that the saw was also damaged. A new PC board is about 70.00 and if the motor is ok then I will likely replace the board.

Thanks again for your input.

10-02-2008, 01:09 AM	#1
Don McLeod Junior Member Join Date: Oct 2008 Posts: 5	Dewalt DW788 blowing fuses a friend of mine asked me to look at his Dewalt DW788 as it had no speed control and would blow the 3 amp fuse after 10=15 seconds of running. When first turned on it runs at full speed and the rheostat does not vary the speed, shortly after running it will blow the fuse. I checked the brushes and also checked the rheostat with a multimeter and it seems to be ok. I suspect that there is a problem with the printed circuit board, is there someway to test the printed circuit board to see if it is operational. Has anyone else with this scroll saw had a similar problem and what was the remedy. Any incite on this problem will be appreciated. Thanks

10-02-2008, 03:12 AM	#2
Forester21 Senior Member Join Date: Jan 2005 Location: Michigan Posts: 1,282	How long has he had this problem? And did it start shortly after a thunderstorm?? __________________ Theresa http://WoodNGoods.etsy.com http://woodngoods.blogspot.com

10-04-2008, 03:10 AM	#4
Dragon scroller and moderator Join Date: Dec 2006 Location: Chertsey, Quebec, Canada Posts: 2,421	Mine was blowing fuses but it started during a thunderstorm and eventually it blew the motor. The service center honored the guarantee and gave me another saw. Diane __________________ Dragon Owner of a Dewalt 788 PuffityDragon on AFSP

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10-03-2008, 08:20 PM	#3
Rug Rat Junior Member Join Date: Oct 2008 Location: Vancouver, WA. USA Posts: 8	I have had the same kind of problems. A new saw and with about 15 hours on it when it started. It would either speed up or slow to about 50 strokes per min then blow the fuse. Factory store replaced the electronics and electrical. new board, speed control,fuse holder, on-off switch and 3 days later the same problems so they replaced it with a new saw. Out of the box it did the same thing. The table was also a very unflat casting. I returned it and got most of my money back and purchased an Excaliber EX-21 and it purrs like a kitten with none of the same problems. This episode took me about 2 mos. to work thru with no solution. Good luck

10-06-2008, 09:45 AM	#5
SNAPPER Dino Join Date: Oct 2007 Location: Fergus Falls,MN Posts: 821	Not sure if the circut boards can be tested. Could be an issue with the windings in the motor. Dean

12-31-2008, 10:23 PM	#6
Don McLeod Junior Member Join Date: Oct 2008 Posts: 5	for the replies. Its been a while since I had a look at the saw but since my first post I've dismantled it and disconnected the motor and it is still blowing fuses. He had been in the hospital for some time and during that time a severe thunderstorm took place and the house next door lost most of their electical equipment, "phones, tv, modems ,routers etc. so it is possible that the saw was also damaged. A new PC board is about 70.00 and if the motor is ok then I will likely replace the board. Thanks again for your input.