Help! Dewalt angle grinder troubles.

Hi, I borrowed a Dewalt angle grinder from a friend. It's model number is DW 400. It's switches break after about ten to fifteen minutes of actual "on" time. I have gone through four switches already. I have been very gentle with it after the first two broke. There is a Dewalt repair center about five miles away that I can get replacement switches. They did replace the first switch that I bought. I also asked them if I could be doing anything incorrectly. They said no. They are closed today so I can't go there until Monday. Has anyone else had this problem? Could another part of the grinder be the reason that the switch keeps failing? Could it be something like a short or maybe improper electrical flow? I could just keep replacing switches. But it is a nuisance. I did buy two of them the last time I was there. Figured it would break again. Maybe I'll have to buy five at a time. I talked to my friend about it and he said that it isn't that old and he rarely uses it. He no longed has the sales reciept. So can't return it. I don't want to pay Dewalt to fix it. I have been replacing the switches myself. Could there be a quick test they could do on it to see if something is wrong? Any thoughts are appreciated. Pete

I bought one maybe 18 months ago...and the switch went flooey after maybe 30 seconds. It worked intermittently for an hour or so and then quit altogether. I never took it back or in for service because I really didn't think I could be polite about it. In fact, I'd forgotten about it until I saw your post.

I simply can't understand why these manufacturers can't figure out how to make a damn switch that works reliably, or a cord that doesn't short out with a few hours use. I won't buy ANYTHING that says PorterCable on it anymore because of the problems I had with the 7529 router, the switch on a 3x24 sander, and the cords on 3 outta five ROS/SpeedBloc sanders that I have either in my shop or at the mesquite outfit.

I've just about decided that if it doesn't say Bosch, Hitachi, or Milwaukee then I can't afford to take a chance on it. And that's a shame...

KC