My Dewalt 788 stops working - please help

[Zhi]

Hi,

My scroll saw stopped working when cut off on a 7/16 oak today, i thought it is the fuse issue as I replaced it a few months ago. But after checked, it is not the issue. It seems the blade is running with very little power, and when I put the wood on the blade, it only viberate, doesn't cutting anything off. If you push down the arm using figer, I got more vibration, still doesn't cut.

I have taken the video here:
DSCN2826.mp4 video by zhi_t - Photobucket

Can anyone pls help me to identify the cause, can I repair it myself.

I appreciate for your kind help.

Zhi

[Zhi]

Some progress made

All,

I made some progress today after dissemble the saw. If you can look at the video, the saw get back to work if I lift the arm. I don't see anything broken at this moment, and don't know where connecting rods drive the arms of the saw. Has anyone ever dissembled the saw and have idea what cause the issue?

http://s182.photobucket.com/albums/x...t=DSCN2828.mp4

Thanks

[barny35]

Check out Rick's Scrollsaw Left side to DeWalt tuneup

[Northerner]

something is deffinetly messed up somewhere, but its not good to run saw without a blade in.
but check out ricks site, he has great info on the 788

[Carter-Johnson]

If you get it cutting, throw away the blade guard. It does nothing but get in your way. I know a lot of folks with DeWalts and not one of them uses it..... Good luck!

Carter

[tgiro]

All,

I made some progress today after dissemble the saw. If you can look at the video, the saw get back to work if I lift the arm. I don't see anything broken at this moment, and don't know where connecting rods drive the arms of the saw. Has anyone ever dissembled the saw and have idea what cause the issue?

http://s182.photobucket.com/albums/x...t=DSCN2828.mp4

Thanks

You are going to have to take the back part of the saw apart. Lots of screws there and you'll need to get some blue locktite, probably once you get it open.

It looks like the linkage between the motor & the drive arm has come loose.

1. Check Rick's site @ scrollsaws.com. He has a wealth of Dewalk 788 info there.

2. DeWALT DW788L Parts List and Diagram - Type 1 : eReplacementParts.com

This site has a breakout of the saw with a parts list. THe parts are shown in proximity of where they are located on the saw so it may help you locate the loose connection.

Good luck.

[sawman101]

Fuse kept blowing on my 788. Dissassembled the saw checked everything several times, finally determining the circuit board went bad. Installed new board at about $80+. Same problem. New motor would cost $210+, so took saw to DW service center to have it rebuilt. They replaced my old, worn, second hand saw with a new one. Cost...$209.99 and 1 year guarantee. They informed me the circuit board was bad. Go figure....At least I had a good functioning saw again, but they didn't give back the money I spent on the cb that claim was bad. I maintain and repair almost everything I have, from the house, to the tractors, and any other machines or tools, but sometimes I gotta throw in the towel and haul it to the repair shop.

[fredfret]

Brushes in the motor could be going bad. Dust in the power switch (not as likely)
Fredfret
wichita, ks

[Zhi]

Thanks all the response, the problem is solved.

Tgiro, you guess is so right. After open the side panel, there is a screw fallen out, pls see the picture. After put it back, i works just fine. There is a guy reported the same issue in the link.


http://i182.photobucket.com/albums/x47/zhi_t/145.jpg

Cheers.

[tgiro]

Thanks all the response, the problem is solved.

Tgiro, you guess is so right. After open the side panel, there is a screw fallen out, pls see the picture. After put it back, i works just fine. There is a guy reported the same issue in the link.


http://i182.photobucket.com/albums/x47/zhi_t/145.jpg

Cheers.

Great Job -- Now start making sawdust & post some pictures of completed projects

Tony

[dgman]

Make sure you apply some blue loctite to that bolt so it does not happen again!