Over the weekend I picked up an F-14 machine that has what I hope is a minor display issue. The game plays fine, but the "C" line on the display is not displaying on both Player 1 and Player 2. (See photo.) All other parts of the display appear as normal.

I have downloaded the manual and started going through the schematics. I've checked the ribbon cable and am pretty sure that is not the issue.

Is there anybody who has encountered this problem before who has a few good ideas about what to check next?

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I completely unplugged the display, removed it, visually inspected it for anything abnormal (all looked good) and checked resistors on the display with my multimeter. All that seemed fine. I think it is probably a problem on the main board of the machine.

The game powers-up and plays just fine. I just checked the ROMs and it does not seem to make any difference. I have removed the display board from the machine and noticed it is model D-11610, which does not match the schematics I found online.

Anybody have an idea if I took a logic probe (I would need to buy one) if that is the right tool to see if data is being sent to the display? I assume that would allow me to isolate whether the problem is on the main board or on the display board.

Thanks for letting me know. Just found the right D-11610 schematics is the manual for Cyclone, and R7 will be the first component I investigate.

Well, popped the batteries out of the holder and they look fine. I have no idea if the battery holder is original, but there is absolutely no sign of corrosion around it. A repair was done to the transistor for the pop bumper, but that is in another part of the board and does not look related. The player 3 display has been replaced, but looks well done and doesn't appear related to the current problem.

I only purchased the machine this past weekend, so I am unsure how long the problem has existed.

Thanks for the advice so far everybody.

Went back one more time with my multimeter and checked each pin leading from microchip U41 through SRC2 up to the pins on IJ22. The part between U41 and SRC2 is what goes under the battery holder. Everything seems to be fine in terms of the circuit being closed. I then double checked each pin for shorts and found no problems. So, I do not think it is related to broken traces under the battery holder.