Quick Turn 10 T1 Alarm 8 F PARAMETER FAULT

I got this alarm a couple weeks ago. Just restarted machine and everything was ok. Thats not working any more. Getting asterisks and random numbers like when the battery goes dead.

Tried the OP 12 reset procedure that I used the last time when the battery went bad. The parameters aren't holding between restarts. Also tried unplugging battery for a while.

It gets more weird. When I set some parameters, others will change with them, like 4 parameters down.
What really scares me is that the program page is blank. No header line. When you try keying in a program, it stays mostly blank.

Battery voltage is good. Power supply voltages are good. I even checked on O'scope to see if there were fluctuations on startup, all voltages started up nicely.

Is it possible the ROM is bad? Or am I not reinitializing the memory correctly?

There was an LX64 board on ebay for $100, so I bought it. It will be a few days before I get it in hand.

Thanks,
Tony

I had an order come in that I needed to run on this machine, so I really dug in this weekend and fixed it:
The multiple parameters changing thing was the clue. The circuit board had a trace corroded away on one of the address lines between some of the RAM ICs. So, whenever the software wrote or read to an address, it was only getting to a subset of the memory locations.
I pulled the data sheet for the RAM ICs and just started doing continuity checks on the address lines until I found this. The address lines run in parallel to all 9 ICs and the chip select/ enable line is used to activate individual chips. A quick jumper soldered in across the open circuit fixed it. I ordered another board (with the identical revision this time) as I don't know if another trace will open up.
I had pulled a mouse nest out of this machine a while back. I suspect a bit of excrement caused this.
-Tony