Check DSQC 661 Power LED, must be green
Check DSQC 663 LED, it´s green if it works OK. If the LED don´t light at all when power on the system, DSQC 663 Axis computer is dead.
If this LED starts flashing red or green, it´s maybe a network cabel fault between DSQC 663-DSQC639 computer.
Or a software issue....