Rap 12 High Speed Modem Test Failure - OKIDATA OF2600 Service Manual

RAP 12 High Speed Modem Test Failure

START
Perform the High Speed Modem Send Test for the transmitter.
Perform the High Speed Modem Receive Test for the receiver.
If you are in RX mode, go to A. If you are in the TX mode, continue here.
Does the modem signal (.14 vac) appear at Pin 1 and 4 of CN7 (network control board)?
YES Replace network control board.
Has the problem been resolved?
YES End of procedure.
NO Replace the main control board.
NO Check for +12 vdc and -12 vdc on the main control board.
+ 12 vdc present at CN5 Pin 14. - 12 vdc present at CN5 Pin 15
Do +12 vdc and -12 vdc appear at these points?
NO Disconnect the cable from CN4 of the printer control board and
measure the voltage at pin 14 and 15 of the disconnected cable.
If +/-12 vdc are not present, replace the power supply board.
YES Replace the main control board.
A
Does the receive signal (.9 vac) appear between L1 and L2 on the line-JU board?
NO Check the line.
YES Does the receive signal (.12 vac) appear between CN7-2 (R) and CN7-1 (GND) of network control
board?
YES Replace the main control board.
NO Is +12 vdc present at CN7- Pin 14 and -12 vdc present at CN7- Pin 15 of the
network control board?
YES Replace the network control board.
Service Guide OF2200/2400/2600
Chapter 2 Failure Analysis
Page: 60