I just followed the guide at pinrepair to remotely mount a battery holder - soldered this in (with a 1n4004 diode in the 4th battery position). At the same time i re-installed a flipper coil i had removed previously, when i powered the game up, there is the sound of the amp starting up but no display or ability to start a game or anything.
The D19 and D21 LEDs come on and stay on and nothing happens with the D20 LED. 1/2 hour previous to this everything was working fine...suggestions??