Way, way back on the playfield of System 3 Gottlieb pinball machines like my 1993 Wipeout is this resistor board that controls the flashing of the pop bumper lights.
This particular board gets VERY HOT during a game and typically leads to the board burning like toast. On my machine it still worked but the board was very brown and even the underside of the playfield was toasty brown.
Time to do something about it before it got any worse. My plan was to replace the resistors with new ones and leave them with much longer leads so they weren’t so close to the circuit board. Also I want to use longer screws with spacers to get the board itself further away from the playfield.
The original resistors were 5 watts 33 ohms 5% wirebound resistors.
My electrical engineer pinhead friend suggested going with 10-watt resistors so that is what I got from Mouser Electronics.
Vishay Wirewound Resistors – Through Hole 10 watts 33 ohms 5% part number – 71-CWO1033R00JE12
Got out the soldering iron, popped off the old resistors and wrangled the new and much larger resistors on to the board.
I then fished around in my screw drawer found some screws that were about 1/4 longer than the original and a bit thicker. Put a 1/4 spacer and put the board back in place and attached the connector.
Seems to be working find. I did see someone online add a fan to the underside of the resistors but I think with my new set up a fan might be overkill. I now have more airspace above and below.