Sansa Clip+ 2GB won't start up, not recognized by the PC

Had the same problem. On a hunch, I tried a different USB cable. I had been using the one I use for my phone’s backup battery. When I switched to a different cable, it was recognized by the PC. I still have not gotten the problem fixed, the updater program fails, but I’m going to try their manual update procedure:

http://kb.sandisk.com/app/answers/detail/a_id/300