Replacing Packard Bell iMedia 5106 Power Supply Unit?

Hi there

My power supply unit has gone on the pb, my brother kindly gave me another pc to use but on the PB my screen plugged into the original power supply and if I just plug it in to an external source it doesn't come off standby when the pc boots up. So...I thought I'd go and get me a new power supply for my Packard Bell but can only find standard ones with the one socket for the power cable. The PB psu has 2 sockets and a 12v DC output for the speakers. Is there a way around my problem or do I have to get an identical psu to replace in order to use my existing screen? I'm not a technical whizz but am not thick so hopefully will understand whatever you throw at me! Thanks