If your e6400 is a Classic version, I have a new power supply from my e6400 Ultra you can have for the price of postage. It's the 43w version, i.e. the pre-RFX power supply. The model is PowDec PTE43-31
Skynet Electronics is the manufacturer for EMU power supplies. You might be able to see if they have a replacement part. They also fix power supplies at a resonable cost. I used them not too long ago. EMU also has a link to a 3rd party company that sells new power supplies but they are really expensive. Good Luck Rob