Resistor kit Williams System 3-7
8 piece, 5 watt 27 ohm power resistor set.
Kit contains 8 power resistors that replace the original 2 Watt 27 ohm resistors on early solid state Williams driver boards. This is referred to in the 1979 Williams Service Bulletin SS-13 shown below.
Solder all 8 of these 5 watt 27 ohm resistors onto your Williams System 3,4,6,7 driver board to prevent future board overheating.
Mount the resistors about 1/4 inch above the board surface to allow for better air circulation.
Also, change all lamps in these machines from #44 to #47 or LED's. They draw about 40% less current and will minimize overheating the driver board in the event of a CPU ‘lock-up’.