Hello Vogons People!

I have a "what would you do next" question:

After "fixing" my 5170, I'm unable to boot it because obviously there is no RTC battery in it yet.
So I'm trying to start it using an Advanced Diagnostics Disk 2.07.

Now the issue is that when I start using the advanced diagnostics disk and answer the battery-question with "No".
The system just locks up. I have no Indication of what is wrong.
Keyboard LEDs are stuck and the monitor only displays a blinking cursor.

Hint: I don't know how to distinguish "regular" 360k disks from 1.2meg 5.25" disks. I have tried some unmarked disks formatted to 40 tracks and some clearly labeled as "Verbatim MD2-HD".
Maybe that is an issue? But on the other hand, it can read it... also I can reproduce the behavior with several different disks.

I have a universal programmer.
Is there a way to check the integrity of the BIOS ROM chips?
Mine are both labeled IBM 1986
61X9266 and 61X9265

Cheers audiocrush

EDIT:
I dumped the BIOS off of mine and my U27 chips content starts with:
6X26OR B OP 9118 61X9266 COPR. IBM 1985
That doesn't really fit the versions that are over on minszerodegrees.net for the Type 3 board.
https://minuszerodegrees.net/bios/bios.htm
However the differences of my U27 ROM to the Variant 1 otherwise are just at addresses 0x0 and 0x10 and at address 0x7000 as well.
The differences in U47 are also at addresses 0x0 and 0x10 as well as 0x7000 and at 0x8000 I have a 00 89 whereas the dump on minuszerodegrees has B7 00 at the end.
It looks like they have different headers but the rest appears to be the same besides the one or two bites that appear to be different...

So I guess they should be fine right?

EDIT2:
I think I'm on to something...
I booted the machine with a DOS 3.30 floppy and then ran the DIAGS.COM from the advanced diagnostics disk
It reads the file, then locks up displaying just a blinking cursor.
When I run SYSCHK it tells me that my base memory is 512KB and my extended memory is -29954KB?
Also CheckIT 2.0 reports this value.
It fails the memory test with an out of memory message immediately. Doesn't do anything. Other tests work fine and pass.
When I let CheckIT display the CMOS Table it says I got -12452KB of memory and -29954KB of extended memory...
Maybe that's my issue?
Anyone knows how I can change that to reflect the real world conditions?