Troubleshooting Based On Problem Type; 1 ] Control Panel And Lcd Problems; 2 ] Fax Problems (For Mfc Only); 3 ] Communications Problems (For Mfc Only) - Brother DCP6690CW Service Manual

4.2.4 Troubleshooting Based on Problem Type

[ 1 ] Control panel and LCD problems

Problem
(1) LCD shows nothing.
(2) Control panel inoperative.
(3) Touch panel inoperative.

[ 2 ] FAX problems (For MFC only)

Problem
(1) No faxes will be able to be sent.
(2) Speed dialing will not work.
(3) Dial does not switch between
tone and pulse.
(4) The ringer does not sound.

[ 3 ] Communications problems (For MFC only)

Problem
(1) No tone is transmitted.
• LCD and its flat cable
• Panel-main harness
• Control panel PCB
• Power supply PCB
• Main PCB
• Panel-main harness
• Control panel PCB
• Rubber keypads
• Main PCB
• Adjust the touch panel with Function code 78 in the
maintenance mode. (Refer to
• Touch panel harness
• Touch panel relay PCB (in the LCD unit)
• Main PCB
• Rubber keypads
• Control panel PCB
• Main PCB
• MJ PCB
• Ordinary dialing function
If it works normally, check the main PCB; if not, refer to item
(1) above.
• Main PCB
• Speaker
• Main PCB
• MJ PCB
• Main PCB
• MJ PCB
4-39
Check:
Chapter 9, Section 9.4.25.)
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