I cleaned the edge (jamma) connector with an eraser and a damp damp q-tip. it was very dirty. The power supply is a dual 9-pin peter chou wattage not determened. i changed the power supply to a single 9-pin suzo-happ, the fan was froze. set the power supply at 5.09v it was at 5.26. guns are at 4.80 better but not at 5.1. the fire but will not calabrate correctly. the right gun will not fire upper left corner of crt but the left one works but won't calibrate correctly. fires just off to the left of the muzzle. opposite for the right gun. To calibrate the guns i have to aim at the "X" at the top left corner then the bottom right. the left gun does great. but off. the right will not work on the left top but will work in the any where else. that is a new gun too. by-passing im not sure where to connect it to.
4.8v is still too low.
Please double check all of the 5v wiring and ground wiring to the guns to make sure it doesn't have any breaks or shorts.
What is the 5v voltage at the headers on the gun I/O pcb?
For bypassing, you will want to run an extra 5v & ground wire from the power supply directly to the guns.
Cut the wire or pop the 5pos 5v/ground pins out at the gun I/O board. Use leads with alligator clips to "jumper" from the power supply to the pins. You'll need something to alligator clip to on the power supply side. I would only do one gun for the initial test.
Long Term No Cut bypass:
If you don't want to cut anything in the harness, you would need 9pos male and female connectors, 4x 5pos moles .100 headers, 1 Z connector (in-line splice connector) for .100 and pin/contacts to match for the above.
The 9pos header everything would wire straight from the male to the female except you need one extra 5v wire lead and one extra ground wire lead. (You could also do 2 wires of each.) Make sure these two (or 4) extra red/black wires are LONG to reach from the power supply to the gun I/O pcb.
The 5pos headers same deal, Blue/White/Green (or brown) wires as the gun I/O header wire through. The 5v and ground leads from the power go to the gun side. The Gun I/O side for 5v/ground is left empty. Z/Inline splice connector here to connect to the gun headers of the harness.