Might be helpful to try a diifferent (externally flashed) EEPROM, sometimes they do become corrupt...

appiah4 wrote on 2023-10-29, 14:35:

What should I poke at to find the issue I wonder?

Assume nothing about the SIMM bank setup. Try 2 sticks in each socket pair. Use 9-chip sticks if you have them, the 3-chip ones are often causing parity issues due to refresh or timing issues.
Connect reset switch and reset the mobo via the switch, see if that changes anything. I don't see a dedicated RTC chip so it's probably in the chipset - there's a 32k crystal in the corner next to NPU socket. The nearby chip must be 4069, it's both low-power oscillator and amplifier for the clock signal. You should be able to measure the 32768Hz output on the gate that's the amplifier (a scope with 10:1 probe can measure it anywhere but with other tools only that gate will provide strong enough signal). Make sure it's there becuase it often clocks some auxiliary logic in the chipset.

https://theretroweb.com/motherboards/s/iqs-ali
trw doesnt have bios dump so that would be nice, and would tell you if its corrupted (checksum)

appiah4 wrote on 2023-10-29, 14:35:

gets stuck on code AA after taking its sweet time on 0D.

AMI BIOS 04/09/90-02/01/91
0D Refresh link toggling passed.
now the funny thing is this version doesnt have AA status code at all 😀

AMI New BIOS; 02/02/91�12/12/91 does have
AA Initialization after E000 optional ROM control is over. Going to display system configuration.

Deunan wrote on 2023-10-29, 17:49:

Make sure it's there becuase it often clocks some auxiliary logic in the chipset.

For example? I've often seen a stopped RTC due to lack of 32.768 kHz and motherboards were working apart from that.