Picked up a PC340 quarter sheet orbital sander at our local Guild meeting for five bucks. I knew when I bought it that it needed a pad (totally missing). But hey, the replacement pad is only 6 bucks or so on Amazon. When I got the sander home and plugged it in, it wouldn't turn over at all. Crap. Why didn't I do that at the Guild before buying it? Since I was into it already for five bucks, I took the sander apart and discovered a frozen bearing on the lower end of the motor. Removal of the bearing, then plugging in the motor confirmed no other problems. I ordered a bearing (aren't those downloadable parts schematics great on many of the manufacturers sites?) along with a pad. $18 total. Parts came in yesterday. Slapped it all back together today and it works great. Total investment $23 and an hour of time. A new 340 is $49 at the borg. Maybe a teeny tiny gloat.
Bob