Williams System 3 thru System 11C High Voltage Parts Kit.
This kit includes the following components:
1N4730A -- Zener Diode, 3.9V - ZR1 and ZR3
1N4763A -- Zener Diode, 91V - ZR2 and ZR4
1N4764A -- Zener Diode, 100V -- Alternate for ZR2 and ZR4 (See Notes below)
1N4004 -- 400V, 1Amp Rectifier - D3 and D4
MJE15030 -- Transistor, NPN - Q1 (SDS-201 Alternate, See Notes)
2N5401 -- Transistor, PNP (MPSD52 Alternate) - Q2
MJE15031 -- Transistor, NPN - Q3 (SDS-202 Alternate, See Notes)
2N5551 -- Transistor, NPN (MPSD02 Alternate) - Q4
RMOS2-39K -- Resistor, 39K ohm, 2 watt (Replaces 39K 1/2 watt and 39K 1 watt) - R1 and R4
RMOS1-1.2K -- Resistor, 1.2K ohm, 1 watt, small form factor (Replaces 680, 1/2 watt) - R2 and R5
RCF1/2-330K -- Resistor, 330K ohm, 1/2 watt - R3 and R6
Kit does NOT include capacitors.
There are currently no readily available replacements for the obsolete SDS-201 and SDS-202 transistors. MJE15030 and MJE15031 transistors can be used to replace these but due to different pin outs - the transistor legs MUST be crossed as shown in the link below. Late versions of the System 11 series boards were designed to use MJE15030 and MJE15031 transistors. Do not cross the legs if the power supply is designed to use MJE15030/MJE15031 transistors!
Use of 1N4763A's in place of 1N4764A's reduces the output voltage by 9 volts. This lowers the voltage to the displays and display drivers to approximately 91 volts. Although there is a minimal reduction in display brightness, the advantage to this voltage reduction is a longer lifespan in both displays and display drivers. Some displays will not work with the reduced voltage. If your display is excessively dim, strobes or doesn't work after rebuilding the supply - install 1N4764A's in place of ZR2 and ZR4.
For improved heat dissipation, 2 watt resistors should be installed with a slight air gap between resistor body and printed circuit board surface.
Ceramic and electrolytic capacitors are not included with base kit.
Most machines used 100uF electrolytic caps for the high voltage, only late model System 11's used 150uF filter caps. Do NOT buy optional capacitors if you are also purchasing the power supply electrolytic capacitor kit as these caps are already included in the power supply kit.
For important information, see:
System 3 thru 7 repair
and System 9 thru 11c repair
For use in the following machines:
System 3: Hot Tip, Lucky Seven, World Cup, Contact, Disco Fever
System 4: Phoenix, Pokerino, Flash, Stellar Wars
System 6: Tri-Zone, Time Warp, Laser Ball, Gorgar, Firepower, Blackout, Scorpion, Alien Poker, Algar
System 7: Black Knight, Jungle Lord, Pharoah, Solar Fire, Barracora, Time Fantasy, Joust, Firepower II, Laser Cue, Star Light
System 9: Star Light, Space Shuttle, Strike Zone Shuffle Alley, Sorcerer, Comet
System 11: High Speed, Alley Cats, Grand Lizard, Road Kings
System 11A: Pinbot, Tic Tac Strike, Millionaire, F-14 Tomcat, Fire!, Big Guns
System 11B: Space Station, Cycle, Banzai Run, Swords of Fury
System 11B: Taxi, Jokerz, Earthshaker, Black Knight 2000, Police Force, Transporter - The Rescue, Elvira and the Party Monsters, Bad Cats, Mousin' Around, Whirlwind
System 11C: Game Show, Roller Games, Pool Sharks, Diner, Radical, Riverboat Gambler, Bugs Bunny Birthday Ball, Dr. Dude (non-WPC).
Effective 1 March 2010 - kits will no longer be provided with printed instructions.
Kit instructions can be found here (Acrobat Format)