Naomi with capcom I/o buttons and joystick not working

[K_Gogetsit]

Just got a new jamma cab in and when I plug in the naomi none of the buttons register or the joystick. When I plug in the regular jamma game everything works fine. The naomi board has no issues in the other cab I’m selling but this newer one something is up. Appreciate the help.

 

[twistedsymphony]

use the test/service buttons on the NAOMI filterboard to enter test mode and make sure it's registering the JVS IO.