the ecu isn't getting power maybe?? since the fuel pump won't come on without the single from the ecu, and neither will the display.
is there any lights or anything on the actualy ecu that light up when powered? turn the ignition and see if the ecu lights up.
after that check for any blown fuses. Then you will probably want to check the earth for the ecu and fuel pump.
You really need a multimeter, to check various signals and voltages to see whats getting power and what isn't