here's some info about it...
F6 = 3 amp slo-blo (incoming 120 volts AC line power)
How the Power Supply Works.
Power comes into the rectifier board from the line cord at connector J2, pins 6 and 7. It then goes to fuse F6 (3 amp slo-blo), and then to the transformer (primary). The transformer splits the voltage into five different AC voltages. Then these voltages run through their own fuse. Some of the voltages (7.8, 12, 49 volts AC) go to a 200 volt, 8 amp bridge rectifier which converts the AC voltages to DC (+5.4, +11.9, +43 volts DC respectively). The 7.3 volts AC stays AC, and powers the game's general illumination. The 173 volts AC that is used for the displays is converted to 230 volts DC by four 1N4004 diodes (CR1 to CR4).