I recently bought a cheap USB hub from Ebay - Chinese made, ridiculously cheap, and came with a small switch-mode PSU not much bigger than a 13A mains plug. After a couple of weeks use, the PSU emitted a loud bang, and showered bits of hot metal and burning plastic across the room. Closer inspection revealed no CE marking; taking it apart, half of one resistor had vapourised and there was clear signs of overheating on other components, with some local melting of the case.
The label identifies it as 'AC Adaptor Model KS868 Input AC 110 - 140V 50/60Hz Output DC5V +-0.2v DC500mA+-30mA' - output connector is a wired-in circular DC connector plug, not a USB cable.
Pictures at https://picasaweb.google.com/1158460...eat=directlink
If you have one of these, obviously please don't use it!
Please repost this on any appropriate forum and to your Facebook contacts - might stop somebody's house burning down, may even save a life.