Basic HTML Version
-10-
MEMORY-CHIP TEST
Press the DIAGNOSTIC button on the left side of the CPU Board. The following
indications are provided.
O-test passed (game returns to Game-Over Mode)
l-IC13 RAM faulty
2-IC16 RAM faulty
3-IC17 ROM 2 faulty
4-IC17 ROM 2 faulty
5-IC20 ROM 1 faulty
6-IC14 Game-ROM 1 faulty
7-IC26 Game-ROM 0 faulty
8-IC19 CPU-Board lockup: also check memory-protect circuit and CMOS RAM
9-Coin-door closed, memory-protect circuit faulty, or IC19 CMOS RAM faulty
Note that ·0· remaining after power turn-on indicates CPU-Board lockup.
SOUND-BOARD SELF-TEST
1. PRESS THE DIAGNOSTIC BUTTON at the top of the Sound Board. Several electronic
sounds should be produced. This sequence of sounds is repeated until the game is
turned OFF and back ON.
2. NO SOUND IN DIAGNOSTIC TEST (but sounds are present in the Self-Test): Check the
sound-select inputs (connector 10J3 and adjacent circuitry) or replace the Sound
Board and rerun the Diagnostic Test (see SOUND TEST above).
3. NEW SOUND-BOARD, SAME SYMPTOM: Check the cables to the CPU Board. If they're
good, replace the CPU Board and rerun the Diagnostic Test.
4. NO SOUND: Check +12V, -12V and +5V-supply voltages on the Sound Board. If
voltages are low (or AC ripple seems too high), replace C27 and C26.
A. ripple of over 0.75 VAC across C27 is excessive
B. ripple of over 0.005VAC across the output of the regulator IC is excessive
4. STILL NO SOUND: Turn the volume control all the way up. With the game turned
on, momentarily place a powered-up AC soldering-pencil on the center tap of the
volume control. DO NOT use a soldering iron of over 40 watts. Cordless models
will NOT work here.
(A) If you hear a low hum, the power-amplifier chip (TDA2002), volume
control and speaker are okay.
(B) If you don't hear a hum, try the test again with the volume control
turned halfway up.