Look at this from a systematic process

1) Are all fuses in the game the correct value, and not blown?
2) Is the power supply producing the correct voltages? You're concerned with +5 and +12 at this point.
3) Unplug everything but 1J17, and power the game on. Do the LEDs stay in the same state they are in now?

After #3, I take the board to the bench, using an old computer power supply that I wire to 1J17 to provide the +5 and +12 to the board. I usually go with Leon's Test ROM on a locked CPU, although I'll admit I often swap the processor before I go to Leon's Test ROM, since it's socketed and I pretty much always have a spare 6802 on hand.

I don't know what your abilities and limits are, so before I go on with more diagnostic information, I thought I'd stop here and see what your thoughts are. A good schematic and a logic probe will come in very handy. I like an actual printed manual - not a PDF - in this case, as PDF schematics are often tough to read.

Any chance you have a logic probe? Or a spare 6802?

I was just thinking that might be a quick way to test the 6802 and see if it's bad. Maybe put the 6802 from the pool sharks in another game and see if the other game boots with the 'suspect' 6802

Clive, Chris, Rob, myself or any number of folks can fix the original board for you.

If you go the Rottendog route, I'm interested in buying your original board. Drop me a line if you go that route.

That opinion is similar to mine, but it depends a lot on the OPs abilities, desires, and intended use of the game.

If a quick flip is intended, a replacement board might be the best choice. Selling off the original board, intact and unharmed, but not working, would offset the cost of a replacement.

If the OP can't diagnose/troubleshoot, for whatever reason, sending it out is going to be the most cost-efficient choice; it'll be less than replacing it with aftermarket, but that does take some time.

And, if skills on diagnosis/troubleshooting are weak, it's likely that the OP will do more damage trying to repair it than they realize, potentially taking a single problem, and introducing several more.

Do you want it quick, or do you want it cheap? Usually, cannot have both.

If you don't have the +100 or -100, the original displays will never work.

At that point, you may want to have the power supply serviced as well - unless you feel like getting a set of LED displays, at which point, all you need is the +5 to power them.

That PS board has seen prior rework. The 2 1/2 watt resistors don't match - R3 has been replaced.

R3 and R4 are common failures on this circuit. Often times, they are all it takes to get the circuit working properly again - but I usually do the entire HV section, one of the few times I shotgun anything.

I don't see any original Sys11 board of any flavor selling for $300 - that seems a bit high to me. I buy, sell and repair quite a few, so I think I've got a pretty decent handle on value. I'd say an original Sys11 MPU, clean, is a 250-275 board on a good day.

The sys11c board used in pool sharks is not a clean original sys11 board. The original sys11 board is much harder to find than an 11c, and much more versatile.

And that's the price I would be selling one for - 100% working and repaired, with a guarantee. That means I'd be buying for a significant amount less.

Depending on price, I might be interested in your non-working boards. Can always use spares!