If your Drifter is blank and not showing the regular segments, it normally means that the power supply fuse to is blown or may be loose.
At your battery's positive terminal, you will find a red 10amp fuse in a holder. This will power the radio memory and the Drifter.
If the 10amp fuse is intact, follow the cable along until you find an inline cylindrical fuse holder.
Twist this open to check the 1amp glass fuse inside.
Before closing, check that the fuse is making good contact with the spring on each side, this can be a cause of the display issue even if the fuse is intact.
Should this not work, we recommend seeing an Auto Electrician, Caravan Repairer, or BMPRO Service Agent.