Purchased an exact replacement for the power cable (less than $20 on Ebay) - scanner powers on!
I've done it, using an adjustable power supply all i needed was 12VDC -
2Amp, the power connector going to the scanner is a 4 pin mini-DIN
male, so i've ripped of the cable from the original bad power module,
cable has inside 2 wires one black one white and a shielding. Black and
schielding are connected together and are going to the minus, the white
one is going to +12V
guess what? .... my scanner is working again
I would replace the power module (adaptor). Same issue happened to my 5400c in early November, too!
Usually answered in minutes!