Thanks a lot for notes; saved a lot of time for me even having the actual schematics.
I looked at all CLUT-MEMCjr connection and also CPU pins; they were all ok. For VRAM pins I just slid probe down the RAM slot until I hear a beep, I don't think that side of CLUT is causing the issue anyway.
No apparent damage and no continuity issue makes fixing issue harder. IMO only a diagnostic ROM, if it exists, can help. Another way is if there we can find out on which instruction or part of FW the computer crashes. Even with that info; we might be able to narrow down the faulty chip and if it is a custom chip good luck finding replacement, buying another 575 logic board would be more economical.