Essilor Instruments APH 550

27
5-15 Nothing is displayed on screen when turning power on
Main causes when nothing is displayed on the screen when turning the power on:
・ Failure of communication cable connecting controller and relay box
・ Failure of switching power supply or LCD panel assy
・ Failure of communication board assy, control board assy, relay board assy
・ Failure of printer harness or control printer harness
Is the power indicator of
the relay box turned on?
NO
YES
No power outlet
【Refer to 5-23】
Nothing is displayed on the screen.
Is the power indicator of
the controller turned on?
Replace the relay board assy.
NO
YES
Is the communication
cable normal?
YES
Replace the
communication cable.
NO
NO
Is something displayed on the screen?
YES
Replace the communication board assy.
Is the screen display normal?
Connect the connector for the controller of the relay box and
the communication connector of the head, and the connector of
the head unit of the relay box and the communication
connector of the controller each with the communication cables.
YES
Is screen display normal?
YES
NO
NO
Is the screen display normal?
YES
NO
OK
To A
(P28)