mine went intermittent - occasionally I'd whack it off my desk and it would start working again, but I got sick of that. I'm now using an AC adapter from a HP Omnibook laptop, found at a Value Village store.

If you can't find one at a thrift shop, i'd grab something like a Cincon TR15 - http://www.mouser.com/catalog/622/1399.pdf - $13 and it's far better than anything you'd find at rat shack.