New board photos added, see the first post. It's the "TK-82C491/GP-4N-D28B1"
Totally unknown board apparently.
I got it to POST (I fixed a dead trace going under the keyboard connector) and swapped the KBC (seems like the old one wasn't working properly somehow), but I can't do much beyond that :
I can access the BIOS setup and do stuff there,but nothing more, as for some reason, the board decides to reboot during the "WAIT" message of the AMI bios.
Also, time doesn't tick in the BIOS, so perhaps the 32.768KHz crystal is dead ? And maybe that's the reason why the board is stuck in a loop.
I'll have to investigate that.
Edit : well i've swapped the crystal, it still doesn't tick ...
I noticed two pins in two of the VLB slots get stuck, I managed to get the board to boot on medias several times, but it's very very hard to get the HDD controller working for some reasons (and when it does the partition of my SD card is totally corrupted). I tried to put several controllers in the slot where there is no pin that get stuck, and it's still not working very well ... The slots look good, but maybe they're dusty, I might try the contact cleaner there.