Hi again 😀 I‘ve made some progress with the board 😀 after some months just laying around, I found some time today to further test it. And indeed it showed some other signs today! It seemed to boot with the keyboard controller inserted, which it never did before.
And one time, it did show me some text on the screen 😁 very briefly though, it Looked like the memory test being performed, I could read „Wait...“ before it rebooted and ended in a boot loop to Debug Code 13, like it did before with the keyboard controller inserted.
So I remembered the tip to solder a wire to fix the broken trace, found the pin and soldered a jump wire. Tomorrow morning I will find out exactly which pins on ISA and the socket these were.
On the first boot after it did initialize my VGA so I could see the Memory test screen again, sadly I didn’t have my camera ready, I could read 128KB OK, then the screen got blank and only
„8042 GATE-A20 ERROR
was shown, and it beeped endlessly.
The soldered wire did not seem to make any difference, I will continue to check the connections tomorrow.
I can see if the vga card is being initialized correctly on the „IREADY“ LED on my debug card, if it is on the whole time on code „2C“ (should be the code for handover to vga bios), it will work, if it goes dark, it won‘t.
If I reset the board it goes into the bootloop, only a cold start works. Why is that?
A question: I wanted to desolder the keyboard bios socket; how do I do that? If I heaten up one pin to remove it, I can’t move it of course, because all other are cold, if I heaten up the secound one, the first one is cold in seconds xD
Are there any other things I need to do?
Does this mean, the Keyboard Bios is indeed dead and I need a new one? Or could it still be a trace issue? Where could I buy the correct one for the board?