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TEST/DIAGNOSTIC PROCEDURES (Continued)
SYSTEM-11 MEMORY CHIP TEST.
A new feature is now included in the Mem-
ory Chip Test for System 11. A diagnosis
of the condition of the "blanking circuit"
now occurs during this testing.
(The
"blanking circuit" protects the displays,
lamps, and solenoids against a hardware
malfunction.) The test requires approxi-
mately 1.5 seconds. Display of an 8 on
the CPU Board LED during the test indi-
cates that the "blanking circuit" operation
is normal; display of a 0 during the test in-
dicates that the "blanking circuit" is NOT
functioning. Following the complete Mem-
ory Chip Test, one of indications listed in
the CPU LED Indicator Codes Table
should appear.
To perform the test,
press the CPU Diagnostic Switch (SW2)
on the edge of the CPU Board.
CPU
LED
Indicator Codes Table
Code
Code Meaning
0
1
Test Passed (game goes to Game-Oyer Mode ).
1
CPU Board lockup; also, check Memory Protect
circuit and U25 CMOS RAM for 'stuck' bits.
2
U27 Game ROM 1 faulty.
(lower ROM, CPU Bd.)
3
U26 Game ROM 2 faulty.
(upper ROM, CPU Bd.)
4
Unused (see "Other or No Indications")
5
Blanking signal 'stuck'; coin door closed; Memory
Protect circuit faulty; or U25 CMOS RAM faulty.
Otheror 2 System Failure: Check 5 VDC Power Supply; U26
No
Game ROM 2 faulty.
Indications
Notes:
1. Zero (0) displayedduring Memory Chip Test (usingCPU Board
switch SW2) indicates that Blanking Circuit is NOT functioning.
2. Eight (8) displayedduring Memory Chip Test indicates that
Blanking Circuit is functioning properly.
SYSTEM-11 SOUND SECTION TEST.
Press the Sound Diagnostic Switch (SW 1) on the CPU Board. Listen for the sound. The sound repeats,
until the operator switches the
Road Kings
game Off and On.
NO SOUND DURING THIS TEST
(but sound can be heard during the Diagnostic Tests).
Check the sound-select inputs (pins 2 through 9 of U9) to see if they pulse during Sound Test 01. Also,
check the -12 V supply voltage on the CPU Board. If this voltage is low (or AC ripple seems too high),
perform the following checks:
1. The gray and gray-green transformer secondary wires for 19.4 VAC.
2. The CPU Board filter capacitor C26 for -12 VDC.
3. The filter capacitor C26 for excessive AC ripple (over 0.75VAC).
If the previous checks did not isolate the problem, turn the Volume Control for maximum output. Momentarily
touch a powered-up AC soldering pencil on the center tap of the Volume Control.
©
b\ U1J'iT 0
(Q)
IN]
DO NOT use a soldering iron over 40 watts. Note also that cordless soldering
irons will NOT work for this test.
Hearing a low hum indicates that the power amplifier (U1, TDA2002), the Volume Control, and the speaker are
operating satisfactorily. Not hearing a hum requires repeating the test with the Volume Control turned part
way down, to determine whether the Volume Control is faulty.