My burgertime stopped working all of a sudden, now it boots to this garbage screen. All the voltages on the board test normal and stable. Re-seating chips didn't help
replace the CPU next then. make sure your sockets aren't dirty. I think Burgertime has 2 boards interconnected doesn't it? reseat whatever connects those.
The CPU is encased in a module on the lower board. So, that's easier said than done. So a search for prior threads on this. Exhaust everything else before tackling the CPU module.
I have found many bad cpu's in the "black box". Its not hard to take them apart and replace the cpu. Its a standard 6502A inside. Extreme care needs to be taken when desoldering the box so no traces are pulled. I made a thread on this a year or two ago.