Fujitsu AUXB04GALH Service Manual page 158

Signal Amplifier (UTY-VSGXZ1 )
Trouble shooting 80
Error Contents :
Main PCB Error
Details :
Condition of occurrence : Communication error between CPU and Network Driver IC
Release condition : Communication is normal between CPU and Network Driver IC
Cause 1 : External noise
Upon pressing RESET button (SW7) or turning on power,
proceed as follows.
(1) If error did not appear, it is not a defect of PCB. Remove the
surrounding noise source.
(2) If error occurs again, check followings other than removing
surrounding noise source.
Symptom :
Error display [ C 1 ]
No operation.
OK
Cause 2 : Signal Amplifier is defective.
Replace Signal Amplifier.
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