During power up on my Data East Star Trek 25 the DMD initially displays "DISPLAY STAR TREK A1.06" with the display code version and Scotty says "Scotty here" and then the screen goes blank and no sound; never displays the CPU code version. I am then unable to enter the service menu, and if I press start, the playfield lights and start button start to cycle on and off rapidly but no game start. Wondering if there is a voltage supply, memory fault, or something else. Anybody ever seen this behavior on a Data East game? Any suggestions would be appreciated. Thanks.

Thank you all for the great suggestions. Sorry I forgot to mention in my original post that diagnostics appear correct on power up: initial state PIA on, +5V on, BLANKING off; final state PIA off, +5V on, BLANKING on. No recent updates or tweaks to the game; turned it off at night and it didn't start the next day. In the past it did however have an occasional intermittent problem of sound board resets during game play with Scotty calling out "Scotty here" a while back that hadn't happened for quite some time. I can sort of activate the slam tilt when it is in this mode causing the playfield lights to go dark when triggering the door slam tilt. Will check voltages and look for fried connectors and grounds and report back any progress. Thanks.

Thank you all for your many great suggestions. The honest answer is I have no idea why it is working again, but while poking around the back box searching for bad connectors, loose grounds, and trying to locate the voltage test pin while wearing my new bifocals (getting old sucks), and then powering up, it then booted normally. I'm guessing I must have a loose connector somewhere in there; not sure why my first go around at reseating connectors did nothing, but it seems ok for the time being. Thank you all for your help!

Ok, so things seemed to be working well for a while until the same thing happened again. Discovered a number of burnt connectors on the power board and a number of apparent hacks on the board. Now the game boots but takes a few minutes after hearing "Scotty Here" before it completes the start up sequence and then the display comes on. So here is the really odd thing, the game call outs are occasionally out of sync with the DMD and play and make no sense; for example, when missing the ship skill shot on ball launch, it will incorrectly shout "Millions", or when the shoot again occurs, the graphics get stuck on the score and don't display the phaser but the sound is correct, or one of my favorites, it randomly eject two balls into the shooter lane even when one is still in play. Maybe a loose ribbon cable? Corrupt game EPROMs? I welcome any thought and comments. Of note, I tried looking elsewhere (https://pinside.com/pinball/forum/topic/data-east-star-trek-25th-anniversary-wont-boot-just-says-scotty-here) but am still scratching my head.