Blank Screen on EFIS2, No engine or fuel data on EFIS1

[Buster]

We have dual Advance Deck 5600s. The left screen boots up, but missing data, see picture. Right screen blank, but the fan is working, so it's getting power. I had hoped it was a loose connection somewhere, but so far that search isn't fruitful. My co-owner thinks we will probably need to send #2 in for repair, but I'm still optimistic we can find the problem. Any help so he's not right, again? Thanks.
One more bit of info that might help. Pressing the lower left button on the blank (Efis 2 on the right) does not start it on battery power as it should.