G4 Mode Communication Ng - Oki OKIFAX4550 Maintenance Manual

4.4.11 G4 mode communication NG

11: G4 mode
communication NG
Check ISDN cable.
OK
Check user/service
setting concerned.
OK
Waveform between CN2-3
pin and 6 pin, and between
CN2-4 pin and 5 pin are
similar to Figure H.13(1/2).
Yes
Waveform of pins 3, 4, 7,
8 of IC3 are similar
to Figure H.13(2/2).
Yes
Waveform of pins 75, 76,
79 of IC2 and pin 53 of
CPU are similar to
Figures H.11(1/3,2/3).
Yes
Waveform of pins 75, 79
91 of IC2 are similar
to Figure H.11(3/3).
Yes
Replace G4N board.
41309401TH Rev.4
NG
Connect correctly
NG
Set parameter correctly
No
Check T1, CN2, R583-586,
R597-600, L4 solderling.
Contact ISDN carrier.
No
Replace IC3 and
check again.
Cause is IC3 chip failure
No
Replace IC1
No
Replace IC2
NG
OK
NG
OK
Re-solderling
Replace IC2
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