How to add a pause switch to a Gauntlet board.
This is a relatively easy project that will allow you to pause any Gauntlet game as long as want and resume exactly where you left off. You can also add a relay to the monitor's AC line to save power and your screen for those long pauses, like when your sleeping.
Three modules (separated by dotted lines) can work independently or together. You can decide which sections you want to build.
View schematic only
The relay is radio shack #275-248. Be very careful installing the relay. If you do it wrong it could ruin your game. First unplug the game. Make sure the Common and Normally Closed contacts are installed inline with one of the monitor's power leads and the normally open contact is not connected. You could use a different relay, but the circuit prefers a 12V/400 Ohm coil. D1,D2,& D3 can be any small signal diodes like a 1N914, 1N4148 or similar. R1,R2,G1, &G2 are red and green LEDs.
I tapped the 15V unreg from the wire heading to the amp board (grey on my machine). The relay is held by the monitor power cable near the existing clamp; I used lots of black tape on the high voltage pins. I soldered wires directly to IC's U13K & U14N. I used single pin sockets on the dual game EPROM high bit pins that were bent up. I put the switches and LEDs in a box mounted to the front of my machine. See my "Gauntlet" link under the "My games" heading for pictures.