WILLIAMS PINBALL SYSTEM 7 DIAGNOSTIC TEST UNIT

Transcription

1 WILLIAMS PINBALL SYSTEM 7 DIAGNOSTIC TEST UNIT Copyright Timothy J. Marsh Page 1

2 TERMS OF USE: THIS DIAGNOSTIC TOOL INCLUDES SOFTWARE, HARDWARE AND/OR INFORMATION (THE UNIT ) FOR USE BY QUALIFIED ELECTRONICS TECHNICIANS. BY USING OR OTHERWISE ACCEPTING POSSESSION OF THIS UNIT YOU AGREE TO DEFEND, INDEMNIFY, AND HOLD THE AUTHOR HARMLESS TO THE FULLEST EXTENT POSSIBLE FROM AND AGAINST ANY AND ALL CLAIMS, DEMANDS, LOSSES, COSTS, DAMAGES, CAUSES OF ACTION, AND OTHER LIABILITIES, BY ANY AND ALL PARTIES, FOR PERSONAL INJURY (INCLUDING DEATH), OR PROPERTY DAMAGE OR LOSS, IRRESPECTIVE OF AUTHOR S FAULT OR NEGLIGENCE, WHICH ARISE OUT OF, OR RESULT FROM THE USE OR POSSESSION OF THE UNIT. CARE HAS BEEN TAKEN IN THE DESIGN AND DOCUMENTATION OF THIS UNIT. NONETHELESS AUTHOR IS NOT RESPONSIBLE FOR ANY LIABILITY ARISING OUT OF AN ERROR, OMISION OR DEFECT IN THE DESIGN OR DOCUMENTATION. THIS UNIT IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND. Williams is a registered trademark of Williams Electronics Games, Inc. Manual Rev. 3.0 Copyright Timothy J. Marsh Page 2

3 Table of Contents I. OVERVIEW... 4 II. TEST ROM no A. Initial Hardware Setup... 6 B. Running Test ROM no III. TEST ROM no A. Initial Hardware Setup B. Running Test ROM no IV. TEST ROM no A. Initial Hardware Setup B. Running Test ROM no V. TEST ROM no A. Initial Hardware Setup B. Running Test ROM no Copyright Timothy J. Marsh Page 3

4 I. OVERVIEW This test unit was designed to test a Williams System 7 MPU and Driver board sets by simulating the various input and output devices associated with a real world Williams pinball machine. To this end, custom Test ROMS have been designed that work in connection with the dedicated Test hardware. These Test ROMS should not be used in an actual pinball machine as unexpected motion and/or damage to person and/or property may result. Copyright Timothy J. Marsh Page 4

5 FIGURE 1 - GENERAL LOCATION OF BOARD CONNECTORS: 1-J-3* 1-J-4* 1-J-5 1-J-6 1-J-7 1-J-2 MPU 1-J-1 1-J-8 2-J-13 2-J-2 2-J-12 2-J-3 2-J-11 DRIVER BOARD 2-J-10 2-J-9 2-J-8* 2-J-7 2-J-6 2-J-5 2-J-4 Indicates pin no. 1 on connector * NOT USED for test purposes. Copyright Timothy J. Marsh Page 5

6 II. TEST ROM no. 0 What is tested: Memory chips IC19, IC16 and IC13 BCD Outputs Display Strobe Outputs PIA5 Sound Board Interconnects Diagnostic 7 Segment LED The MPU does not need to be connected to a Driver board to perform the tests on Test ROM no. 0. A. Initial Hardware Setup 1. Replace the Game EPROM at IC17 with TEST ROM no. 0 ROM inserted into IC17 on System 7 MPU Copyright Timothy J. Marsh Page 6

7 2. Connect all Test Fixture cables to the MPU and DRIVER (if used) boards as shown in FIGURE 1 (above). 3. Connect +5VDC to the Test Fixture * Do NOT turn on the power supply yet just connect it. 4. Jumper the Rest Circuit Jumper the BOTTOM lead of R27 and the BOTTOM lead of C23. Copyright Timothy J. Marsh Page 7

8 B. Running Test ROM no. 0 STEP 1: Turn on the +5VDC power supply and toggle the power switch on the Test Fixture to ON. Upon application of power the 8 segment LED on the MPU should flash 0 three times in a row. This indicates that the test ROM has successfully booted and is running. Note: During the initial memory tests the program does not use any commands that require a stack. This is because a stack uses memory and we don t want to rely on this until we can verify that the memory is operational. Unlike system 6 devices, system 7 requires both IC16 and IC19 to be operational in order to utilize the stack, because the memory spans both chips. If the memory is bad then the rest of the test will not function properly and the results of the remaining tests should be ignored. This is due to the fact that the remaining tests require the use of a valid stack region of memory. 1. Memory IC19: The MPU writes a value to the first and last memory addresses of IC19 and then reads the value back. If the values read equal the values written then the memory is good. The MPU will display a 9 on the 8 segment LED. If a 9 is not displayed then the test has failed. 2. Memory IC16: The MPU writes a value to the first and last memory addresses of IC16 and then reads the value back. If the values read equal the values written then the memory is good. The MPU will display a 6 on the 8 segment LED. If a 6 is not displayed then the test has failed. 3. Memory IC13: The MPU writes a value to the first and last memory addresses of IC193and then reads the value back. If the values read equal the values written then the memory is good. The MPU will display a 3 on the 8 segment LED. If a 3 is not displayed then the test has failed. 4. Display Strobe Outputs (I-J-7 & I-J-6): 4 outputs on PIA 1 control all 16 display strobe outputs with the help of 4-16 decoder (IC8). The Test Fixture applies +5 VDC to the Copyright Timothy J. Marsh Page 8

9 positive terminal of the test LEDs. In normal operation the MPU holds the pins on I-J-6 and I-J-7 high (at +5V) so no current flows. When the MPU wishes to trigger a display strobe output the MPU connects the corresponding pin on I-J-6 or I-J-7 to ground. Once connected to ground the circuit is completed and the corresponding LED illuminates. Note that by default display strobe 1 is ON. This is because the decoder turns on its first output (output 0) when the input on all 4 control lines are low the default state. This means that upon startup strobe 1 will be illuminated this is normal. o Each LED should illuminate and then turn back OFF (one after the other). If an LED is always ON (i.e., stuck on ) then the voltage applied to that LED by the test harness is always finding a path to ground. Attention should be paid to PIA 1 Port A PA0-PA3, the decoder IC8, as well as the terminals at I-J-6 and I-J-7. If an LED never illuminates (i.e., stuck off ) then the voltage applied to that LED is never finding a path to ground. Attention should be paid to PIA 1 Port A PA0-PA3, the decoder IC8, as well as the terminals at I-J-6 and I-J BCD Outputs (I-J-5): In normal operation the MPU applies voltage to pins on I-J-5 (one after the other). When power is applied to a pin the corresponding LED will light. o Each BCD LED should illuminate and then turn back OFF (one after the other). If an LED is always ON (i.e., stuck on ) then voltage is always being applied to that LED by the MPU. The most likely causes of such a failure is that PIA 1 is bad and needs to be replaced or there is a problem with the trace that connects PIA 1 to I-J-5. If an LED never illuminates (i.e., stuck off ) then voltage is not being applied to that LED by the MPU. The most likely cause of such a failure is that PIA 1 is bad and needs to be replaced or there is a problem with the trace that connects PIA 1 to I-J MPU 8 Segment LEDs: Numbers 1 through 9 are sequentially displayed on the 8 segment LED. The 8 segment LED is then reset to display 0 o Possible causes of errant diagnostic LED operation include: LED segment is burned out IC2 is bad and needs to be replaced. There is a bad solder joint or trace on the board. PIA 1 is bad and needs to be replaced. 7. Sound Board Interface Outputs (I-J-8): In normal operation the MPU applies voltage to pins on I-J-8 (one after the other). When power is applied to a pin the corresponding LED will light. o Each LED should illuminate and then turn back OFF (one after the other). Copyright Timothy J. Marsh Page 9

10 If an LED is always ON (i.e., stuck on ) then voltage is always being applied to that LED by the MPU. The most likely causes of such a failure is that PIA 5 is bad and needs to be replaced or there is a problem with the trace that connects PIA 5 to I-J-8. If an LED never illuminates (i.e., stuck off ) then voltage is not being applied to that LED by the MPU. The most likely cause of such a failure is that PIA 5 is bad and needs to be replaced or there is a problem with the trace that connects PIA 5 to I-J-8. Cycle Power to restart test. Index of Components with each Tested Element: Element Tested Connector (pin) Transistors PIA/Port/Output Other Components Toggle BCD A2 1-J-5 (9) N/A 1 B PB0 N/A Toggle BCD B2 1-J-5 (8) N/A 1 B PB1 N/A Toggle BCD C2 1-J-5 (7) N/A 1 B PB2 N/A Toggle BCD D2 1-J-5 (5) N/A 1 B PB3 N/A Toggle BCD A1 1-J-5 (4) N/A 1 B PB4 N/A Toggle BCD B1 1-J-5 (3) N/A 1 B PB5 N/A Toggle BCD C1 1-J-5 (2) N/A 1 B PB6 N/A Toggle BCD D1 1-J-5 (1) N/A 1 B PB7 N/A Toggle Diagnostic LED no. 1 N/A N/A 1 A PA5 LED no. 1 Toggle Diagnostic LED no. 2 N/A N/A 1 A PA4 LED no. 2 Toggle Display Strobe 1 1-J-7 (9) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 2 1-J-7 (7) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 3 1-J-7 (6) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 4 1-J-7 (5) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 5 1-J-7 (4) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 6 1-J-7 (3) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 7 1-J-7 (2) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 8 1-J-7 (1) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 9 1-J-6 (9) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 10 1-J-6 (8) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 11 1-J-6 (6) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 12 1-J-6 (5) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 13 1-J-6 (4) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 14 1-J-6 (3) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 15 1-J-6 (2) N/A 1 A PA0,1,2,3 IC6 Toggle Display Strobe 16 1-J-6 (1) N/A 1 A PA0,1,2,3 IC6 Comma 3&4 1-J-8 (1) N/A 5 B PB6 Copyright Timothy J. Marsh Page 10

11 Comma 1&2 1-J-8 (2) N/A 5 B PB7 Sound Select 4 1-J-8 (8) N/A 5 A PA4 Sound Select 3 1-J-8 (9) N/A 5 A PA3 Sound Select 2 1-J-8 (10) N/A 5 A PA2 Sound Select 1 1-J-8 (11) N/A 5 A PA1 Sound Select 0 1-J-8 (12) N/A 5 A PA0 III. TEST ROM no. 1 What is tested: Solenoids 1-8 ( connector 2-J-11) Solenoids 9-16 (connector 2-J-9) Special Solenoids (connector 2-J-12) Flipper Control (connector 2-J-12) Special Solenoid Switch Inputs (connector 2-J-13) A. Initial Hardware Setup 1. Perform the Initial Hardware Setup detailed in connection with Test ROM no. 0 (above) with the exception that you will replace the Game EPROM at IC17 with Test ROM no. 1 (instead of Test ROM no. 0). 2. Connect a Driver Board to the MPU. 3. Jumper +5 VDC to pin 37 (4 th pin from the left) on the 40 pin interconnect connector I-J-1 as shown below: Copyright Timothy J. Marsh Page 11

12 B. Running Test ROM no Turn on the +5VDC power supply and toggle the power switch on the Test Fixture to ON. 2. The 8 segment LED on the MPU should flash 1 (For Test ROM no. 1) three times in a row. This indicates that the test ROM has successfully booted and is running. 3. Solenoids 1-16: The Test Fixture is always applying +5 VDC to the positive terminal of the LED. In normal operation the MPU sends a signal to the appropriate output circuitry on the driver board. The output circuitry, via a pair of transistors, then connects the negative terminal of each LED to ground (one after the other). Once connected to ground the circuit is completed and the LED illuminates. o Each LED should illuminate and then turn back OFF (one after the other). If an LED is always ON (i.e., stuck on ) then the voltage applied to that LED ( solenoid ) by the test harness is finding a path to ground. The most likely cause of such a failure is that one of the (2) transistors associated with that output are short circuited and need to be replaced. If an LED never illuminates (i.e., stuck off ) then the voltage applied to that LED is never finding a path to ground. The most likely cause of such a failure is that one of the (2) transistors associated with that output are open circuited and need to be replaced. Other possible (but less likely) causes of errant LED operation: The PIA chip associated with the errant output(s) is bad and needs to be replaced. If a group of LEDs illuminate but nothing else noticeable occurs then it is possible that the MPU board failed to properly load the test logic into memory. Try a different Test ROM to see if it is, in fact, a problem with the MPU board boot sequence. 4. Special Solenoids 1-6 (solenoids 17-22): The Test Fixture is always applying +5 VDC to the positive terminal of of the LED. In normal operation the MPU sends a signal to the appropriate output circuitry on the driver board. The output circuitry, via a pair of transistors, then connects the negative terminal of each LED to ground (one after the other). Once connected to ground the circuit is completed and the LED illuminates. o A note about the Special Solenoids: The Special Solenoids are intended to be triggered directly by switches on the playfield during normal game play. This hard wired design was implemented because the MPU was considered too slow for time sensitive activities like pop bumpers. Nonetheless, Williams included the ability to control the Special Solenoids via the MPU. Accordingly the Special Solenoids have the ability to be fired by either a switch closure or the MPU. The Test ROM s automatic cycling of the Special Solenoid LEDs is testing Copyright Timothy J. Marsh Page 12

13 MPU control of the Special Solenoids. Remember, few (if any) games actually relied on the MPU to control the firing of the Special Solenoids during normal game play. As such, even if the MPU fails to properly control the Special Solenoids the game may play correctly. Switch control of the Special Solenoids will be tested later using the Special Solenoid Selector Switch. o Each LED should illuminate and then turn back OFF (one after the other). If an LED is always ON (i.e., stuck on ) then the voltage applied to that LED ( solenoid ) by the test harness is finding a path to ground. Check to see if the Special Solenoid Selector Switch is set to that output. If it is, then move the switch to the off position and see if that corrects the problem. If the selector switch is not the cause then the most likely cause of such a failure is that one of the (2) transistors associated with that output are short circuited and need to be replaced. If an LED never illuminates (i.e., stuck off ) then the voltage applied to that LED is never finding a path to ground. The most likely cause of such a failure is that one of the (2) transistors associated with that output are open circuited and need to be replaced. Other possible (but less likely) causes of errant LED operation: The PIA chip associated with the errant output(s) is bad and needs to be replaced. 5. Left and Right Flipper Relay: The Test Fixture applies +5 VDC to the positive terminal of the Left and Right Flipper Relay LEDs. In normal operation the two Flipper Relay LEDs connect to ground via contacts in the ice-cube Flipper Relay. During this test the MPU momentarily turns OFF the Flipper Relay. This causes the Left and Right Flipper LEDs to turn OFF (simultaneously) as they lose their connection to ground. o Note: The Flipper Relay is pulled in as soon as the MPU boots so these two LEDs are normally ON. o Possible causes of errant operation include: Fault in the Flipper Relay logic circuit. Verify that the flipper ice-cube relay on the driver board appears to be pulling in and out. Cycle Power to restart test. Copyright Timothy J. Marsh Page 13

14 Manual Test Operations: 1. Special Solenoids 1-6 (solenoids 17-22): At any time during Test 1 (or even when using Test ROMs 2 or 3) you may test the hard wired control of the Special Solenoids via the Special Solenoid Selector Switch. Simply select the number of the Special Solenoid to be tested using the selector switch. The LED corresponding to that solenoid should illuminate until the selector switch setting is changed. The Test Fixture is always applying a voltage to the positive terminal of LEDs The selector switch mimics the playfield switches used to pull in the Special Solenoids. Closure of the switch connects the negative terminal of the LED to ground (via the same pair of transistors tested in step 2 of the automatic sequence). Once connected to ground the circuit is completed and the LED illuminates. o If the Special Solenoids operate correctly in step 2 of the automatic sequence but fail this manual test then the problem is likely very close to the connector 2- J-13 (such as a bad solder joint on the corresponding connector pin). Copyright Timothy J. Marsh Page 14

15 Index of Components with each Tested Element: Element Tested Connector (pin) Transistors PIA/Port/Output Other Components Toggle SOL 1 2-J-11 (4) Q14, Q15 4 A PA0 IC1 Toggle SOL 2 2-J-11 (5) Q16, Q17 4 A PA1 IC1 Toggle SOL 3 2-J-11 (7) Q18, Q19 4 A PA2 IC1 Toggle SOL 4 2-J-11 (8) Q20, Q21 4 A PA3 IC1 Toggle SOL 5 2-J-11 (9) Q22, Q23 4 A PA4 IC2 Toggle SOL 6 2-J-11 (3) Q24, Q25 4 A PA5 IC2 Toggle SOL 7 2-J-11 (2) Q26, Q27 4 A PA6 IC2 Toggle SOL 8 2-J-11 (1) Q28, Q29 4 A PA7 IC2 Toggle SOL 9 2-J-9 (9) Q30, Q31 4 B PB0 IC3 Toggle SOL 10 2-J-9 (7) Q32, Q33 4 B PB1 IC3 Toggle SOL 11 2-J-9 (1) Q34, Q35 4 B PB2 IC3 Toggle SOL 12 2-J-9 (2) Q36, Q37 4 B PB3 IC3 Toggle SOL 13 2-J-9 (3) Q38, Q39 4 B PB4 IC4 Toggle SOL 14 2-J-9 (4) Q40, Q41 4 B PB5 IC4 Toggle SOL 15 2-J-9 (5) Q42, Q43 4 B PB6 IC4 Toggle SOL 16 2-J-9 (6) Q44, Q45 4 B PB7 IC4 Enable Special SOLs N/A N/A 4 B CB2 IC7, IC9 MPU Toggle Special SOL 17 2-J-12 (7) Q1, Q2 3 B CB2 IC6, IC9 MPU Toggle Special SOL 18 2-J-12 (4) Q3, Q4 3 A CA2 IC6, IC8 MPU Toggle Special SOL 19 2-J-12 (3) Q5, Q6 2 B CB2 IC6, IC8 MPU Toggle Special SOL 20 2-J-12 (6) Q7, Q8 2 A CA2 IC6, IC8 MPU Toggle Special SOL 21 2-J-12 (8) Q9, Q10 4 A CA2 IC7, IC9 MPU Toggle Special SOL 22 2-J-12 (9) Q11, Q12 1 B CB2 IC7, IC9 Flipper Relay (LEFT) 2-J-12 (2) Q13 N/A N/A N/A IC8, RELAY IN4001 Flipper Relay (RIGHT) 2-J-12 (1) Q13 N/A N/A N/A IC8, RELAY IN4001 SS1 Toggle Special SOL 17 2-J-13 (5) Q1, Q2 N/A N/A N/A IC6, IC9 SS1 Toggle Special SOL 18 2-J-13 (3) Q3, Q4 N/A N/A N/A IC6, IC8 SS1 Toggle Special SOL 19 2-J-13 (2) Q5, Q6 N/A N/A N/A IC6, IC8 SS1 Toggle Special SOL 20 2-J-13 (4) Q7, Q8 N/A N/A N/A IC6, IC8 SS1 Toggle Special SOL 21 2-J-13 (8) Q9, Q10 N/A N/A N/A IC7, IC9 SS1 Toggle Special SOL 22 2-J-13 (9) Q11, Q12 N/A N/A N/A IC7, IC9 Copyright Timothy J. Marsh Page 15

16 IV. TEST ROM no. 2 What is tested: Lamp Columns 1-8 Source Drivers (connector 2-J-5) Lamp Rows 1-8 Sink Drivers (connector 2-J-7) Lamp Power connector 2-J-4 Lamp Ground connector 2-J-6 A. Initial Hardware Setup 1. Perform the Initial Hardware Setup detailed in connection with Test ROM no. 1 (above) with the exception that you will replace the Game EPROM at IC17 with Test ROM no. 2 (instead of Test ROM no. 1). Turn on the +5VDC power supply and toggle the power switch on the Test Fixture to ON. B. Running Test ROM no Turn on the +5VDC power supply and toggle the power switch on the Test Fixture to ON. 2. The 8 segment LED on the MPU should flash 2 (For Test ROM no. 2 three times in a row. This indicates that the test ROM has successfully booted and is running. 3. Lamp Columns 1-8 Source Drivers: The Test Fixture supplies a connection to ground on the negative terminal of COLUMN LEDs 1-8. In normal operation the MPU sends a signal to the appropriate output circuitry on the driver board. The output circuitry, via a pair of transistors, then connects the positive terminal of each LED to the power source at connector 2-J-4 (one after the other). Once connected to power at connector 2-J-4 the circuit is completed and the LED illuminates. o Each Column LED should illuminate and then turn back OFF (one after the other). If an LED is always ON (i.e., stuck on ) then the column output is shorted to power. The most likely cause of such a failure is that one of the (2) transistors associated with that output are short circuited and need to be replaced. If an LED never illuminates (i.e., stuck off ) then the voltage applied to that LED is never connecting to power. Check that there is voltage on connector 2-J-4. If there is voltage then the most likely cause of such a failure is that one of the (2) transistors associated with that output are open circuited and need to be replaced. Other possible (but less likely) causes of errant LED operation: Copyright Timothy J. Marsh Page 16

17 The PIA chip associated with the errant output(s) is bad and needs to be replaced. If a group of LEDs illuminate but nothing else noticeable occurs then it is possible that the MPU board failed to properly load the test logic into memory. Try a different Test ROM to see if it is, in fact, a problem with the MPU board boot sequence. 4. Lamp Rows 1-8 Sink Drivers: The Test Fixture applies +5 VDC to the positive terminal of ROW LEDs 1-8. In normal operation the MPU sends a signal to the appropriate output circuitry on the driver board. The output circuitry, via a pair of transistors, then connects the negative terminal of each LED to the ground provided by connector 2-J-6 (one after the other). Once connected to ground the circuit is completed and the LED illuminates. o Each Row LED should illuminate and then turn back OFF (one after the other). If an LED is always ON (i.e., stuck on ) then the row output is shorted to ground. The most likely cause of such a failure is that one of the (2) transistors associated with that output are short circuited and need to be replaced. If an LED never illuminates (i.e., stuck off ) then the voltage applied to that LED is never finding ground. Check that connector 2-J-6 is grounded. If connector 2-J-6 is grounded then the most likely cause of such a failure is that one of the (2) transistors associated with that output are open circuited and need to be replaced. Other possible (but less likely) causes of errant LED operation: The PIA chip associated with the errant output(s) is bad and needs to be replaced. Cycle Power to restart test. Index of Components with each Tested Element: Element Tested Connector (pin) Transistors PIA/Port/Output Other Components Toggle COLUMN 1 Source 2-J-5 (8) Q62, Q63 3 B PB0 IC13 Toggle COLUMN 2 Source 2-J-5 (9) Q64, Q65 3 B PB1 IC13 Toggle COLUMN 3 Source 2-J-5 (6) Q66, Q67 3 B PB2 IC13 Toggle COLUMN 4 Source 2-J-5 (7) Q68, Q69 3 B PB3 IC13 Toggle COLUMN 5 Source 2-J-5 (3) Q70, Q71 3 B PB4 IC14 Toggle COLUMN 6 Source 2-J-5 (5) Q72, Q73 3 B PB5 IC14 Toggle COLUMN 7 Source 2-J-5 (1) Q74, Q75 3 B PB6 IC14 Toggle COLUMN 8 Source 2-J-5 (2) Q76, Q77 3 B PB7 IC14 Copyright Timothy J. Marsh Page 17

18 Toggle ROW 1 Sink 2-J-7 (1) Q46, Q47 3 A PA0 IC19 Toggle ROW 2 Sink 2-J-7 (2) Q48, Q49 3 A PA1 IC19 Toggle ROW 3 Sink 2-J-7 (3) Q50, Q51 3 A PA2 IC19 Toggle ROW 4 Sink 2-J-7 (4) Q52, Q53 3 A PA3 IC19 Toggle ROW 5 Sink 2-J-7 (5) Q54, Q55 3 A PA4 IC19 Toggle ROW 6 Sink 2-J-7 (6) Q56, Q57 3 A PA5 IC19 Toggle ROW 7 Sink 2-J-7 (9) Q60, Q61 3 A PA6 IC12 Toggle ROW 8 Sink 2-J-7 (8) Q58, Q59 3 A PA7 IC12 V. TEST ROM no. 3 Note: This test uses the Lamp Matrix LEDs to provide feedback related to the operation of the Switch Matrix. Accordingly, you should run Test Rom no. 2 to check for proper operation of the Lamp Matrix before running this test. What is tested: Switch Column Source Drivers (connector 2-J-2) Switch Row Sink Drivers (connector 2-J-3) A. Initial Hardware Setup 1. Perform the Initial Hardware Setup detailed in connection with Test ROM no. 1 (above) with the exception that you will replace the Game EPROM at IC17 with Test ROM no. 3 (instead of Test ROM no. 1). B. Running Test ROM no. 3 Turn on the +5VDC power supply and toggle the power switch on the Test Fixture to ON. The 8 segment LED on the MPU should flash 3 (For Test ROM no. 3) three times in a row. This indicates that the test ROM has successfully booted and is running. The Text Fixture provides a connection between each of the Column Source Driver Outputs and a corresponding terminal on the Column Selector Switch (SS1). For example, the Column 1 output is connected to position number 2 of SS1. The common terminal of SS1 is connected to the common terminal of the Row Selector Switch (SS2). The Row Sink Drivers (inputs to the MPU) are then each connected to one of the positions on SS2. The MPU sends a signal out of a first Column output, for example Column 1, and then scans each Row input 1-8 to see if the output signal makes it back as Copyright Timothy J. Marsh Page 18

19 an input. If the output is passed back to the MPU as an input then it means that SS1 is set to the outputted Column and SS2 is set to the Row that successfully passed the signal back to the MPU. The MPU then interrogates the next Column output until all Columns have been scanned for each Row. The test then starts over. Whenever an input signal is observed the MPU turns on the Lamp Matrix Column and Row LEDs corresponding to the positions of SS1 and SS2. An example is illustrative of the operation: o If SS1 is set to the COLUMN 4 position and SS2 is set to the ROW 2 position then an output signal can only be returned and detected by the MPU when the Column 4 output is triggered by the MPU and the Row 2 input is read. Any other combination of Column and Row will not allow the signal to pass from the Column output to the Row input. The MPU triggers a Column output and then scans each of the Row inputs. A signal outputted by the Column 4 output will appear on the Row 2 input. The MPU will then activate the Lamp Matrix Column 4 and Row 2 LEDs. Any discrepancy between the Column and Row LEDs and the positions of SS1 and SS2 is indicative of a problem with the Switch Matrix. There are no transistors associated with the switch matrix so the problem is likely associated with a bad solder joint, a broken trace, or PIA number 2. Index of Components with each Tested Element: Element Tested Connector (pin) Transistors PIA/Port/Output Other Components COLUMN 1 - Output 2-J-2 (9) N/A 2 B PB0 IC17 COLUMN 2 - Output 2-J-2 (8) N/A 2 B PB1 IC17 COLUMN 3 - Output 2-J-2 (7) N/A 2 B PB2 IC17 COLUMN 4 - Output 2-J-2 (6) N/A 2 B PB3 IC17 COLUMN 5 - Output 2-J-2 (5) N/A 2 B PB4 IC18 COLUMN 6 - Output 2-J-2 (3) N/A 2 B PB5 IC18 COLUMN 7 - Output 2-J-2 (2) N/A 2 B PB6 IC18 COLUMN 8 - Output 2-J-2 (1) N/A 2 B PB7 IC18 ROW 1 - Input 2-J-3 (9) N/A 2 A PA0 IC15 ROW 2 - Input 2-J-3 (8) N/A 2 A PA1 IC15 ROW 3 - Input 2-J-3 (7) N/A 2 A PA2 IC15 ROW 4 - Input 2-J-3 (6) N/A 2 A PA3 IC15 ROW 5 - Input 2-J-3 (5) N/A 2 A PA4 IC16 ROW 6 - Input 2-J-3 (4) N/A 2 A PA5 IC16 ROW 7 - Input 2-J-3 (3) N/A 2 A PA6 IC16 ROW 8 - Input 2-J-3 (1) N/A 2 A PA7 IC16 Copyright Timothy J. Marsh Page 19