Been a while since I have fixed one of those game titles.

First check your power supply voltage. Many shooters require that the +5vdc be no more than +5.1 (+5.2 MAX) or severe damage to the main PCB and the gun PCB will occur (This 100% true with all SAMMY Games such as Deer Hunter). Check the power supply at the board and adjust to +5.1vdc

The other problem that shooters have is the monitors need to be tuned to the guns. Try adjusting the contrast and brightness levels while shooting and see if the gun starts to shoot in diferent spots with each adjustment.

Also go into the menu system and clear all data and perform a "Factory Default" after. Some of the Midway games require you to clear the data (RAM) before calibrating controls. This eliminates stored data points from conflicting with new settings.

Good luck.

Thanks!! Ill try to check voltage tommorow. But about guns... There is no light diods, they work on potentiometers. So there is nothing to do with monitor brightness. And ok, ill try to do factory reset. So till tommorow!