Dremel 398 is dead as a Dodo.

go to Http://www.dremel.com/en-us/AttachmentsAndAccessories/Pages/Attachments.aspx

No.. the issue issue is the switch inside. when your Dremel 4200 stop working, press firmly the grey area between the speed selector and the brush housing. I think this a defect in the design of the 4200.

Hi it sounds like you have a brush worn out. I would change out the brushes first and go from there. Brushes are relatively cheap and it is a good investment to check out first. You can get brushes from almost any hardware store that sells Dremel parts and accessories.

you can change the brushes by opening the two little doors one on the top and one underneath the tool and the brushes will just fall out. you can then pop the new brushes in and replace the little doors. if you are looking for where to bye the brushes then just go on ebay or bye from dremel direct. im not sure how much dremel want for the brushes but i paid £7.58 on ebay.
i hope this has helped.

I would think that just the brushes, they should slide freely in the slot. check also the condition of the armature for arcing or raised commutator bars.

Dremel has all their replacement parts right on the shelf at walmart, brushes, caps, chucks, the works. You found the cap, the brush is a little carbon square attached to a wire with a spring on it. Real simple. Buy a pair and get it fixed up. My favorite tool.

On a 4000 there is a thermal fuse at the base of the motor from the brush housing. They are cheap to replace. these are replacing fuses on alot of electronic devices. the fuse is a microtemp g7f01 110c.

ebay.com or www.craigslist.com
Try to find a used one maybe?

It could be the fuse between the brush and variable speed control switch. I have the same problem and found the fuse blown. I am hoping that I can replace the fuse without having to buy the complete speed control unit which is about $17.00 from Dremel. If yours is still under warranty you could send it back. If I can find a fuse for mine I will let you know where to get them. joatmontag

clean the slots that hold the brushes, sometimes they get cloged and the springs do not push the brushes all the way to the armeture.