Player button lights problem on S2000 (double row of buttons)

[Wadsworth]

I love this forum.
I am attempting to breathe life into a 5 reel, 9 line, 90 CM Triple Butterfly 7's slot out of storage for 7 or 8 years.  After replacing a missing power distribution box and installing a new 3v coin battery, the game booted up.  Then, after a key chip config, it seems to play fine.  The validator takes bills, and the printer prints on cashout.  However, none of the buttons light and the solenoid does not release the pull handle. 

When I opened a few buttons, I found that the led's were lit, but very very dim (12.7 v).  I think all of them are lit even when the main door is open. The bulbs tested normally bright in another machine.

I haven't found any loose plugs or damaged wires.
I cold-swapped the 2 door I/O's and the cabinet I/O, one at a time from another machine to no avail. 
I tried another power supply.

What am I missing?

[Wadsworth]

Just to add, although the voltage at the bulb measures 12.7 v, there is not enough current to light an incandescent, and the led is super dim.
Also, I swapped another distribution box with no change.
I just noticed the candles aren't working but the bulbs are good, and the service button makes a pleasant beep when pressed.
I'm going to have a martini.

[Wadsworth]

Could it be that the software is for a single row of buttons?  Base SB100924, Game SG000598, Version VS011GX1, DSPL002, SNDF DSV00042.

[brianfink]

Your software looks correct. Led buttons will normally be dimly lit when not on. I would try unplugging the cylinoid since it isn't working. If that does not help then I would suspect the main board, or you have a short somewhere. Do the buttons actually work when you push them?     

[Wadsworth]

Brian, you were absolutely right.  It was the main board.  Changing the MPU fixed everything!

Thanks for your input!