Oki OKIPAGE 8p Maintenance Manual page 153

B-1 Initialization error and not restored
• Replace ROM.
• OK?
• No Is the 7.065-MHz clock signal being put out to pin 3 of OCS1?
• No
• Yes Failure of CPU
B-2 Program ROM error
• Replace ROM.
B-3 Resident RAM error
• Are negative pulses being put out to Pin 14 , 30, 31 (DRAS0-N , DCSA1-N, DCAS0-
N) of DRAM?
• No
• Yes Are the signals at pins, 2 TO 5 , 7 TO 10 , 33 TO 36, 38 TO 41
(D00-P to D15-P) of DRAM being changed?
• No
• Yes Replace DRAM.
B-4 EEPROM error
• Replace EEPROM.
• OK?
• No Failure of CPU
B-5 Fuser error/ Thermistor Open error/ Thermistor Short error
• Is the heater on?
• No
• No Failure of CPU
B-6 Watchdog timer timeout occurs frequently.
• Replace ROM.
• OK?
• No Failure of CPU
Replace OSC1 (CST 7.065M).
Failure of CPU
Failure of CPU
Is the voltage at Pin 116 (HTON-P) of CPU 5V?
• Yes Replace Q3 or TR2
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