Hi.

Don't break any warranty seal until you got an "open it to check cable connections" mail back from support.
What you could do though is the following:
Since the screen filter is user-replacable, you could take of the fascia and check if you can see anything broken on the front of the display board.
The most likely cause for a completely dark (turned off) display seems to be a drop to the floor with the gas fill nipple breaking of the VF display. Either that or (if you didn't let your empeg drop) a blown fuse.

Also, if you have one of the later MkII(a)s with the warranty seals on the drive tray instead of the top lid, you could also remove the top lid carefully and check if you can see anything broken there. But I do not recommend this.

cu,
sven