Namco system 12 tekken tag input problem help!

[Planeptsuntsun]

hello guys i have a namco system 12 tekken tag with input problems the P2 is all good. the player 1 LP (Button 1) automatically triggers when i push the RP ( Button 3) or the LK( Button 4 which is in the kick harness area) does anyone know how to fix or troubleshoot this?

the LP(Button 1) only triggers when i push RP( Button 3) or LK( Button 4)

i already check my jamma line, edge and pins and its all in good condition.

i appreciate any help and suggestions thank you

 

[twistedsymphony]

A lot of these boards were modified with jumper wires from ops does yours have any modifications?

Failing that the next thing to check are any resistor packs or logic ICs or other parts between the JAMMA edge and the IO chip... if those all check good then the IO chip itself is bad.

 

[Planeptsuntsun]

A lot of these boards were modified with jumper wires from ops does yours have any modifications?

Failing that the next thing to check are any resistor packs or logic ICs or other parts between the JAMMA edge and the IO chip... if those all check good then the IO chip itself is bad.

For now i saw some jumper wirew from kick to jamma i"ll gonna undo it and see if something will change

 

[Planeptsuntsun]

Update: i already undone the jumper wires from kickharness still no good

 

[Franco23444]

Like @twistedsymphony said, a resistor could have gone bad. Check those. I think someone posted a similar issue around here and fixing the resistors worked for them.