Assumed your engineer tried reboot if not:
Try turning off the box from power, plug power back in at the same time as pressing back up on receiver. Keep hold of back up until all lights light. Wait for reboot, (10 mins).
When the receiver comes back on, sometimes it takes a minute or so for second feed to show a signal.
If this fails, you have a dead box.
Brought a few back to life with above
