Resurrection... of the thread. 🙁
Unfortunately with other keyboard controller, the behaviour is still same - all leds are lit up.
I also went through all cache chips. I now have TL866II Plus, which can also test SRAMs. All chips are good.
No beeps, debug card doesn't show any numbers/codes (only garbage value right from the beginning, if shutdown and powered on immidiately)
On debug card CLK is on, IRDY is off, FRAME is on, RESET is on at the beginning for brief moment, then off.
The KB fuse is okay, showing 0 ohms with multimeter.
@Tiido, yes, it's Sis471 board. (Y)
So if you have any other ideas to check, let me know! 😀
"640K ought to be enough for anybody." - And i intend to get every last bit out of it even after loading every damn driver!