Sorry for the necro-posing, but I am a Necromancer. 😀 Sad there are no more post how it went with this particular board. I can confirm the problem might have been in loose pins on the QFP chips. I had dead board of the same type and one chip (SIS 503) had almost left the board. The other one had some bad pins as well.
However I ma still struggling a bit. The board runs only if the L2 cache is set to WT mode. If I set WB in bios, it always get stuck on post screen right before booting.
Pretty weird issue...

Solved - I have flashed older bios from 1995 (the last one is 1998) and the cache and all the other functions are working OK now and the board behaves as it should.
The bioses all available here;
https://theretroweb.com/