Williams System 9 - 11

Note: This page is a work in progress. Please help get it to a completed state by adding any useful information to it.

1 Introduction

Put system info here

Williams System 9 Board Set

2 Games

2.1 System 9

• Space Shuttle
• Sorcerer
• Comet

2.2 System 11

• Grand Lizard
• High Speed
• Road Kings
• Gold Mine (Shuffle Alley)

2.3 System 11a

• Pinbot
• Millionaire
• F-14 Tomcat
• Fire!
• Fire! Champagne Edition

2.4 System 11b

• Big Guns
• Space Station
• Cyclone
• Banzai Run
• Swords of Fury
• Taxi
• Jokerz!
• Earthshaker
• Black Knight 2000
• Police Force
• Elvira and the Party Monsters
• Bad Cats
• Mousin' Around!
• Whirlwind

2.5 System 11c

• The Bally Game Show
• Pool Sharks
• Rollergames
• Diner
• Radical!
• Dr. Dude
• Riverboat Gambler
• Bugs Bunny's Birthday Ball

3 Technical Info

The System 11 Board Set

4 Problems and Solutions

4.1 Power Problems

Replacement power supply If using the Rottendog WDP011A power supply for Williams Cyclone or Big Guns, you may have to move the +12v jumper from the bottom jump to the top. If your machine has GI but doesn't boot (only the 5v light on the CPU is lit) and is one of these two games, that is the most likely reason.

4.7 Display problems

System 9/11 High Voltage Section Repair

WARNING: This circuit uses high voltages. Don't continue, unless you are confident in your diagnostic abilities.

Check Voltages

If all displays are blank, your high voltage (HV) section may not be working. On the Power Supply Board, use a DMM set to DC volts with the - lead grounded, probe the following connector pins to determine if the HV section needs repair. If the display fuse, F1 is blowing, you should remove the applicable display connector (with power off) before testing the voltages.

If you have Power Supply D-11883 or D-12246:

3J2 pin 1 = -100 volts DC
3J2 pin 3 = +100 volts DC

If you have Power Supply D-8345-xxx:

3J5 pin 3 = -100 volts DC
3J5 pin 4 = +100 volts DC

If the test points are more than about 5 volts out of spec, then your HV section may be malfunctioning. Check the table below for a solution.

Troubleshooting table

Symptom	Possible Cause	Replacement
0V ON BOTH +100/-100 lines	Check F1	1/4 Amp SB
0V on +100V line	Open Diode D3	1N4004
	Open Q2	2N5401
	Shorted Zeners	1N4730A and 1N4763A
	Open Q1	MJE340
0V on -100V line	Open Diode D4	1N4004
	Open Q4	2N5551
	Shorted Zeners	1N4730A and 1N4763A
	Open Q3	MJE350
F1 1/4 Amp Fuse Blows	Bad Capacitor at C1 and C3	100uF,150V
	Shorted Display	Display Glass*
	Shorted UND7180	UDN7180*
	Shorted UDN6118	UDN6118*
+118V on +100V line	Shorted Q1	MJE340
-118V on -100V line	Shorted Q2	MJE350
* located on display board

Display Fuse F1 Blows

Testing the UDN Chips

If the display fuse is blowing, you should check the display board for shorts before connecting a new or rebuilt power supply to the display board, as a shorted display or chip can damage a good power supply. Remove the display board from the system. The display characters are driven by the two types of UDN chips, the UND7180 & UND6118 (or UDN6184). Locate these chips (there are several) on the board and test them with your DMM set to diode check. Clip your + (RED) lead to the ground trace of the board. Probe the UDN chips as shown in the diagram. If any shorts are read in the tested pins, the display should not be connected to the power supply until the shorts are corrected.

Shorts Are Found in UDN Chip Test
If a short reading is found in the tested pins (don't test the pins labeled 'dont care'), the UDN chip should carefully be desoldered and removed from the board. Take care to preserve this chip, as they are nearly impossible to find and expensive to replace. Now install an IC socket in its place. Repeat the test with no chip installed. If the short is gone, then the UND chip needs to be replaced. If the short remains, then the display glass needs to be replaced.

Displays Test With no Shorts
Once the displays are tested and shorts are eliminated, we can proceed with the HV section repair.

Replacing the components in the HV Section
Since there are not that many components, if you are having problems isolating the fault, a quick solution is to replace all the components in the HV section. If only one side (+ or -) is failing, it is possible to rebuild only the failing side. Check the parts section of the wiki to find suppliers, and get the replacement parts for one or both failing sides:

Part	+Side Part	-Side Part	+,-Location
Transistor	MJE340	MJE350	Q1,Q3
Transistor	2N5401	2N5551	Q2,Q4
Zener diode	1N4730A	1N4730A	Z1,Z3
Zener diode	1N4763A**	1N4763A**	Z2,Z4
Resistor	39k Ohm,1W	39k Ohm,1W	R1,R4
Resistor	680 Ohm,1/4W	680 Ohm,1/4W	R2,R5
Resistor	330k Ohm,1/2W	330k Ohm,1/2W	R3,R6
Capacitor	0.1uF,250V metal polyester	0.1uF,250V metal polyester	C2,C4
Capacitor	100uF,150V	100uF,150V	C1,C3
**This is a 91V Zener to reduce the voltage to prolong display life

Remove and replace HV components

• Clip the old components from the board (make sure you have new ones first).
• Use one of the desoldering methods to remove solder from the holes.
• Stuff board with new components.
• Check for correct orientation on transistors, diodes and the large capacitor if you replace it.
• Leave a little space under components for air flow.
• Bend leads on components so they won't fall out when board is inverted for soldering.
• Double check that all the correct parts are in the correct places and properly oriented.
• Solder the parts to the board
• Clip excess off leads

NOTE ON INSTALLATION OF THE MJE340/MJE350 TRANSISTOR
The MJE340/MJE350 is the heat-sinked transistor. On most Williams boards, this transistor pin configuration is not the same as the original part. It will need to be installed vertically with heat sink attached to the transistor only. The transistor will sit at about a 45 degree angle so the legs can be lined up to fit in the correct holes. Check your board and insure correct orientation before soldering in place.

Ready to test

To test the rebuilt power supply, return to the "Check Voltages" section of this guide.

4.8 Sound problems

System 11 games are known to have some amount of hum. An easy thing to test is to make sure all boards are secured tightly with all screws. This will insure the boards have a proper ground.

Another cause of hum could by an inconsistent +5 volts from the power driver board. An indicator of this being the cause of your hum would be the game occasionally resetting as well. Replacing caps C8 and C10 on the power board may fix this issue.

5 Repair Logs

Did you do a repair? Log it here as a possible solution for others.