So I just picked up a Space Shuttle last weekend; PF is pretty rough, hardtop incoming. Otherwise, even after transport, it was perfectly playable. Two nights ago. Fired it up tonight, and initially it would start a game and play normally, but the audio was the continual speech test loop: “one, two, three, four, airlock, whatever whatever” I pulled and reseated roms, plugs, pressed the test buttons (which, the speech sound test button does restart the audio sequence), unplugged, pulled batteries, restarted… and the current game state is:
Power up
Score displays go from normal to every 0 turning to a 1
Plays one sound effect
Goes into speech test mode (one, two, three, four, airlock, whatever…)
Lights are not consistent with attract mode; general illumination is on and flippers are powered, cannot start a game but can flip the flippers.
Really confused about this given that it played perfectly last time it was powered up, though I will note even then the score displays we’re all odd numbers, I did notice that. I hadn’t noticed until tonight that 0s show up initially and then give way to ones in the score display. Any thoughts on where to go from here?

Here’s a link to what it’s currently doing. Again, it was playing perfectly a few days ago, then was powered off for two days, and started this when it was turned back on. Any suggestions would be appreciated.

https://vimeo.com/765453902

Thank you PINTEC. Reseating u11 gave no change; swapping u11 and u17 made the machine not boot at all. (Swapping them back returned the machine to the state in the video.) Does this indicate that one of those microprocessors is bad? Should I just replace them both? SR10 looks brand new.

They are both 6808 processors. If I place the processor from u17 into u11 and leave u17 out, machine powers up with just general illumination, and the sound loop plays when SW2 is pressed.

Thanks so much for your help. I’ll order some tomorrow and update when they arrive!

Turns out I do have a couple MC6802p's at work; can I use one of those in u17 instead of ordering another 6808?

Awesome. Thanks for your help, I’ll try it out tonight! Cheers

That did it, the machine is working now! Now there are two more playability issues on the machine:

The displays are still only showing odd numbers, which not only affects the scoring but affects my ability to perform tests and such...

When a game is started, the machine kicks one ball into the shooter lane, but once a ball is locked, it kicks two balls into the shooter lane. This makes multiplayer impossible because when one of those two balls is drained it moves on to player two, even though there's still a ball in play. I know the shooter lane switch is working, what else do I check? Hoping to get this machine fully restored with new plastics, hardtop and get these playability issues fixed by the end of the month, when I'm hosting an IFPA sanctioned tournament!