Quoted from okgrak:
Is anything else effected by this? Seems like an expensive fix just to boost some dim coin slot leds.
Nope, everything else about the game is unaffected. If you look at the schematic there is a 12V circuit dedicated to just the 2 coin door LEDs (there are other 12V that feed starter LED, launch LED, etc.)
I agree that it was an expensive mistake, and I have debated whether or not to leave it "as is", to try to repair the board myself, to route a 12V feed directly from the power supply, or to replace the board. I've decided to replace the board to return the game back to fully working order, and consider it a lesson learned.
I'm no electrician, but the way it was explained to me is that the issue was caused by drawing too much current on the coin door circuit causing some component on the control board to fail.