Main Pcb - Brother 8250P - FAX B/W Laser Printer Service Manual

1.14 Main PCB

(1) For the FAX-8250P/MFC-9050 (French version only)/MFC-9550/MFC6650MC, take the
battery ASSY*
(2) Remove the screw from the main PCB.
(3) Slightly lift up the main PCB and disconnect it from the low-voltage power supply PCB.
(4) Disconnect the following harnesses from the main PCB:
• Speaker harness (2-pin, P7)
• Laser diode harness (5-pin, P6)
• Toner sensor harness (4-pin, P5)
• Polygon motor flat cable (5-pin, P4)
• NCU harness 2*
• NCU harness (12-pin, P14)
• Solenoid harness (blue) (2-pin, P8)
• Hook switch harness*
• Main motor harness (6-pin, P16)
• High-voltage power supply harness (12-pin, P20)
• Fan harness (2-pin, P3)
• CIS harness (7-pin, P19)
• Scanner motor harness (5-pin, P17)
• Panel-main harness (6-pin, P21)
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* The FAX-8250P/MFC-9050 (French version only)/MFC-9550/MFC6650MC has a Ni-MH
battery ASSY. Only when you need to replace the main PCB, disconnect the battery harness.
After installing a new main PCB, you may need to make settings (e.g., calendar clock and
voice messages) to be stored in the RAM. If you need to replace the battery ASSY, do not
disconnect the harness in this disassembly step. Doing so with the power cord unplugged will
lose the settings stored in the RAM. Refer to Section 1.1.
n n
Reassembling Notes
• Route the hook switch harness (red), solenoid harness (blue), and main motor harness through
three latches "w," "y" and "z."
• At the rear side of the main cover, route the harnesses as shown on the next page. Hook the
speaker harness on the left-hand battery support.
version only)/MFC-9550/MFC6650MC, route the battery harness as shown on the next page to
hold the three harnesses (scanner motor harness, CIS harness and speaker harness) for
preventing the battery harness from interfering with the top cover sensor actuator.
• Tape the CIS harness and panel-main harness at location "a" and tape the scanner motor at
location "b" as shown on the next page.
• For the FAX-8250P/MFC-9050 (French version only)/MFC-9550/MFC6650MC, when trans-
porting the main PCB, be sure to remove the battery ASSY (Ni-MH battery) from the PCB.
Failure to do so may result in a short circuit, overcurrent flow or fire.
• After you replace the main PCB, be sure to follow the flowchart given on page IV-34.
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out of the supports at the rear of the main cover.
2
(6-pin, P13)
3
(red) (2-pin, P9)
2
(* Provided on the European, Australian, Indonesian, and Asian versions.)
3
(* Not provided on the FAX-8250P/MFC-9050.)
For the FAX-8250P/MFC-9050 (French
IV - 32