For a replacement of the same power rating ECM40UT31
Or with a higher power rating, which is the one I would go for given the small difference in price ECM60UT31
A picture may help, its not clear what you mean about the soldered wire. Normally the earth lead is soldered to the PSU but the live and neutral go into a two pin connector.
Also be aware that you should also replace the capacitors on the backplane/motherboard at the same time as the PSU.