you must have the POST dipswitch turned off if it's doing this. let me play with it in MAME, I'll get you what you want your dipswitches set to first. I would pull the board and make sure all the roms are seated in good first.
T-unit boards require a little bit of [preventative] maintenance. they're pretty much a shitty design, Midway left all the through-hole components too long, and the legs have a tendency to get bent flat and touch nearby components... that usually accounts for weird graphic glitches or possibly even what you're going through, so inspect the board for any bent pins. so long as you have the mounting feet you don't even need to cut them, just bend them back upright with a precision flathead and make sure that while it's in your possession you never set the board flat without the feet again lol.
the roms will be susceptible to chip creep of course, but I've seen in a couple instances where the roms formed corrosion on them, probably from where they were stored or operated previously. fine sandpaper across the legs on both sides will correct that issue. I think these came with all eproms, if you have any exposed windowed roms, and it was in a bright place, they could also get corrupted. that's why you want the POST dipswitch enabled so it can tell you if anything's throwing up errors.
your voltages are always key of course, but only the +5 will matter, I know the Y-unit boards have test points, but I haven't looked at any of my T-unit stuff in great detail lately (that and my memory's kinda wiped right now from a work-related accident lol) but you'll want to check the +5 at the roms for an accurate reading. you already cleaned your JAMMA edge, so I doubt you're having any current issues.
I'd start there first. I'll get you the settings in a bit.
EDIT: use these. I'm assuming you have a 2 player cab, so I used that setting.