You have probably measured voltage rails so that CPU, memory and chipset gets the juice they need? It would probably be a good idea to measure actual power pins on the slots/chips, not just from the regulator or power connectors incase there are damaged or broken traces.

And as you seem to have scope, also check the crystal so you have a clock. I’d also try to probe some chipset data pins and see if there is any activity and life there (also CLK signals). This could at least help to narrow down where the fault is.

Edit: Batman has dallas, am I correct? It may be that if the battery is empty, the board refuses to boot. I don’t know if this applies to Batman, but there are boards that won’t boot with empty CMOS battery or no battery installed.

Thanks for your input.

I already removed the dallas and checked with another one. I checked clock and Vcc also. I also assume that without one of both, the CPU wouldn't get warm and do anything on the bus...
I'll probe the chipset the next days when i find some time.

ok, really strange.
I connected a logic analyzer to the address and databus.
D8...D15 is D0-D7 of the isa-bus.
D0...D7 is A0-A7.

recv means "recovery jumper is set to the right"
12 is the next screenshot, recovery jumper to the left.

What i don't understand:
Everything after the Jump (EA 5B E0 00 F0 FF) is wrong (12.png)
The jump is read correct, but executed wrong.
I checked the bios. Both the original that came with the board and another one i put together with the BI0/BI1 of the update package.

Has anyone a known-working bios i can flash directly?

Anyway, what comes after the jmp isn't what's there.

TheRetroWeb should have a bios file for that board. these early 430LX boards are super finnicky IME. does the PCI bus check out okay? IIRC the system crystal controls the FSB AND PCI clock and an issue in either circuit could cause bizarre behaviour. the ISA bus is clocked seperately, however.

LeFlash wrote on 2025-09-19, 14:18:

ok, really strange. I connected a logic analyzer to the address and databus. D8...D15 is D0-D7 of the isa-bus. D0...D7 is A0-A7. […]
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ok, really strange.
I connected a logic analyzer to the address and databus.
D8...D15 is D0-D7 of the isa-bus.
D0...D7 is A0-A7.

recv means "recovery jumper is set to the right"
12 is the next screenshot, recovery jumper to the left.

What i don't understand:
Everything after the Jump (EA 5B E0 00 F0 FF) is wrong (12.png)
The jump is read correct, but executed wrong.
I checked the bios. Both the original that came with the board and another one i put together with the BI0/BI1 of the update package.

Has anyone a known-working bios i can flash directly?

Anyway, what comes after the jmp isn't what's there.

Hi, not long ago I asked to copy the BIOS from a working motherboard, but if I understand correctly, you can't extract it (save a copy).
Always if I understand correctly, you have to start the card, in Recovery BIOS mode, if I'm not mistaken there is a jumper, and you need a 3.5" floppy disk reader connected, with the floppy containing the BIOS, which is on the Internet.
If you want you can try to contact other users of Vogons, who have BATMAN motherboards, personally I don't have this motherboard, but I was trying to help a friend of Vogons, who has quite the same symptoms.