I've been running my H8000FW for some time without any problems. As of about a couple weeks ago, when turning on the unit it would sometimes start with a blank screen. The problem became progressively worse to the point where it would start with a blank screen7 out of 8 times.
I held down 8 at start up hoping it would fix the problem but it didn't. I tried to update to the new OS from 5.5 beta to 5.61 beta. The unit was in the processes of erasing at 30% then the update quits with the screen reading "Bad Block Address (E4012)"
I tried to update again only this time i got this message
"Address Error, Program D8D3D4, Data FFFFFFFF"
I've updated my eventide before so I know this problem is not because of my card/adapter.
I'm afraid it sounds like some kind of hardware problem. Try the upgrade a few more times. If unsuccessful, either send the unit in for service, or, if you are handy, remove the top and wiggle all socketed parts in their sockets, especially U106 (square chip in center of board).