Sound Test

The sound test indicates the condition of the music and sound effects circuits on the audio PCB. The sound microprocessor resets at the beginning of the test. You will hear the first sound, which is "chip test," three seconds after the test starts.

After the microprocessor is reset and you hear the first sound, the number of game sounds and the sound CPU status information appear. If the CPU is good, the word Good appears. If you get an error message at any point in the sound test, see Table 2-7 for more information.

The test cycles through the following tests:

■ Speech Chip Test

Use the left joystick to select the sound and the left jump button to listen to them.

Also check the operation of the coin mechanisms on this screen. As you press down the auxiliary coin switch on each coin mechanism, one of the zeroes in current coin values changes to one.

Table 2-7 Locations of Bad Sound RAMs and ROMs

Location on


Error Message

Audio PCB

Cause or Comment

Music Chip Time Out

4H :

Sound CPU Interrupt Error

2D, JE, 6K

Sound CPU RAM 1 Error


Sound CPU ROM 1 Error "


If this message appears when you enter the sound test, the sound processor can-: not proceed any further. Press the left jump button to exit the test.

Communications Error #1


Counts the number of errors caused by the audio or game PCB. This means that the SCOM chip (part no. 137526-001) on one of these boards is bad. CAUTION

; The SCÔM chip is a CMOS IC and is static-sensitive. If you do not handle it properly you can permanently damage it.

Communications Error *2

Probably the audio PCB is disconnected from the game PCB, or the chip at ID is not inserted into its socket.

Sound Processor Not Responding

A major problem with the audio PCB. If you cannot enter the self-test, the harness may be disconnected between the audio PCB and the game PCB.

Chapter 3

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