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Factory Settings Restored.
This message indicates that the CMOS RAM (U8) no longer retains any custom Pricing or Game
Adjustment settings and has reverted to factory defaun settings. Generally, the following CPU
checks will isolate the cause of the CMOS RAM memory failure. The voltaces at pin 28 and pin 26
of U8 should be +5V (game turned On) and at least +4V (game turned Off). When the voRage
drops below +4V, memory reset occurs. Check the batteries and battery holder. Be sure that the
batteries are good and that there is no contamination on the battery holder terminals. Turn the
game OFF, and use an ohmmeter to check diodes 01 and 02 on the CPU Board. 01 should read
o
ohms when forward-biased and infinite ohms when reverse-biased. 02 should read 15 ohms
when forward-biased and infinite ohms when reverse-biased. (Readings taken with an analog
meter.)This message can also indicate that there is an open diode on a 50V coil and noise is
entering the circuit.
Opto Theory
The opto receiver (Photo Transistor) should be approximately 0.1 - 0.7 volts when the opto beam
is unblocked and approximately 11 - 13 vons when the opto beam is blocked. The opto transmitter
(LEO)
should always be approximately 1.4 volts.
Note:
The transmitter
(LEO)
is larger than the
receiver (Photo Transistor); it protrudes further from its case.
LED Board
Transmitter
1.0 • 1.4 Volts
Photo Transistor Board
Recelyer
0.1 - 0.7 Volts Unblocked
11 . 13 Volts Blocked
GREEN
o
WHITE
BLACK
INFRARED BEAM
CPU L.E.D.'s
The CPU has three L.E.D.s located on the upper left side of the board 019, 020, and 021. On
game power-up 019 and 021 turn on for a moment then, 019 turns off and 020 starts to blink
rapidly. 021 remains on. The system has detected a problem
if
the following happens:
CpU Board L.E.p. Error Codes
Center
L.E.O.
blinks one time
Center
LE.O.
blinks two times
Center
L.E.O.
blinks three times
U6 ROM Failure
US RAM Failure
U9 Custom Chip Failure
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UgQn Game Turn-On:
1 Beep
=
Sound Board O.K.
2 Beeps
=
U2 Failure
3 Beeps
=
U3 Failure
4 Beeps
=
U4 Failure
5 Beeps
=
U5 Failure
6 Beeps
=
U6 Failure
7 Beeps
=
U7 Failure
8 Beeps
=
U8 Failure
9 Beeps
=
U9 Failure
DEMOLITION MAN
1-37