My PSU died yesterday evening. Thanks to this forum, I knew this was inevitable so a new PSU was already on order with NewIT. However, I needed the plug to be up and running ASAP.
Fortunately I had an old ATX power supply lying around which is able to supply a whopping 30A at 5V (via the RED wire). Plenty for what I need. After some handywork everything was connected and the plug works fine again.
For the record: If anybody else is going to attempt to use a PC power supply, you need to be aware of the fact that the GREEN and a BLACK wire need to be connected to each other for the PSU to work. Otherwise it'll just remain in the standby mode. I simply inserted a strategically clipped paperclip into the motherboard connector, shorting the green with a black, and put some tape over it to keep it in place.http://en.wikipedia.org/wiki/ATX
NewIT claims that the new PSUs should be available for shipping around August 4th, so I hope this solution will work for a week or so.