Did the eBay seller give you any sort of guarantee it was working? If so then you should contact him/ her and advise them the machine isn't working properly. Sounds to me like the fan inside doesn't want to do its thing and the chips are overheating.
One other option (if the seller refuses to do anything and you don't want to go into a dispute with it at eBay) is make some use of the machine you bought for parts and maybe replace the drive in the (barely) functioning one.