I'm in.. just picked up a star trek .sorting out some issues .

I recently bought a 91 star trek data east.
For 1 the dmd durring normal scoring only will freeze up and make no sense and do jumbled up scoring ect .but will go into video mode no problem during game play ..
In attract mode it's perfect..
I purchased two new ribbon cables to be safe from different companies.. same thing ..soon as I shut the game down or reseated the plugs it's good for a while ?
Another is switch 27 and 28 were not registering in switch test .?? I replaced one switch of the two and now it has a error come up telling me there bad ? I tried putting the original switch back in and it still comes up as a error but stil won't register in manual switch test ? I'm gonna try to replace the other switch that was not registering wich was switch upper left hole top switch number 28.
Any assistance is greatly appreciated.

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Ok I replaced both switch 27 and 28.. same thing ??I notice switch 29 has no diode ?

Mod I made for star trek. Spok with six shooter and a spotlight on spok for extra ball...

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I've been sorting out issues on my 91 star trek
.originally i was having display issues .
Certain times only on scoring the display would get jumbled and freeze up..
I decided to install updated game and display roms .
The problem went away and actualy worked perfect ..
Now at certain times never consistently when a ball drains a new ball will shoot into the shooter lane and automatically fire into the pf with no notification on the dmd ect .
I'm going to tear into this issue tonight .I'm wondering if anyone has had this issue or were to start lookin.
I'm going to try the original 91 game rom for starters.
Thank you ..