Troubleshooting Based On Problem Type; 1 ] Control Panel And Lcd Problems; 2 ] Fax/Telephone Problems (For Mfc Only) - Brother MFC990CW 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/Telephone 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.
(5) No phone call can be made with
the handset.
(6) No phone call can be made with
the cordless handset.
* For models with handset
1
For models with cordless handsets
*
2
• LCD and its flat cable
• Panel-main harness
• Control panel PCB-to-PCB harness (for models with touch
• 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
• Touch panel harness
• Touch panel relay PCB (in the LCD unit)
• LCD unit
• Main PCB
• Hook switch
• Rubber keypads
• Control panel PCB
• Main PCB
• MJ PCB
• Ordinary dialing function
• Main PCB
• Speaker
• Main PCB
• MJ PCB
• Curled cord
*1
• Handset
• Main PCB
• Cordless handset
*2
• Cordless PCB
• Main PCB
• MJ PCB
panel)
maintenance mode. (Refer to
*1
If it works normally, check the main PCB; if not, refer to item
(1) above.
4-34
Check:
Chapter 9, Section 9.1.4.29.)
Check:
Confidential