Is it recapped? Some of the SMD caps just fell off mine when I poked it. Recapping it solved all problems. This thread had documentation:
https://www.arcade-projects.com/threads/tekken-tag-tournament-namco-system-12-recap-repair-restore.4415/
It would be neat to have a overview of what Taito Type X4 USB IO boards are released, what their features are and what firmware is used for what game.
SDSlot ID
ID 1
ID 2
Game/Comment
K91012581
M9009288A
K9101258C
J9100647A
M9009153A
K9101258A
J9100647A
Love Live
Love Live...