Data Sent Through The Centronics I/F Cannot - Oki OKIPAGE 12i Troubleshooting Manual

B-21 Data sent through the centronics I/F cannot be received.
• Is the signal at Pin 11 (BUSY-P) of the connector (CENT) low?
• No
• Yes
• Yes Is the level of the signal at Pin 1 (PSTB-N) of the connector (CENT) change
at data reception?
• No
• Yes Are the signals at Pin 5 (PACK-N), Pin 13 (PERROR-N) of IC11 (74LS07)
respectively low and high in on-line mode?
• No
• Has the problem been solved?
• No
• Yes Failure of IC1 (MHM2029-005K).
B-22 Cover open occurs frequently.
• Are Pins 2 and 3 of the diode D501 open?
• Yes
• No Is the connection of the connector (POWER), correct?
• No
• Yes Failure of IC1 (MHM2029-005K).
Is the signal at Pin 3 (PBUSY-P) of IC11 (74LS07) change at data
reception as shown below?
PBUSY-P
• No Failure of IC1 (MHM2029-005K).
Replace IC11 (74LS07).
Verify the connection of I/F cable or the operation of the host
computer.
Replace IC11 (74LS07).
• Yes End.
Replace D501.
Replace the connector (POWER).
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ON-LINE OFF-LINE
Low High