Brother DCP-L8400CDN Service Manual page 432

1.3.24 Laser unit test pattern print (Function code 68)
<Function>
This function is used to print the laser unit test patterns and check if there is any failure in the
laser unit.
<Operating procedure>
(1) Press the 6 and 8 keys in this order in the initial state of the maintenance mode.
"PRINTING" is displayed on the LCD, and one laser unit test pattern (see the figure
below) is printed.
(2) When this operation is completed without an error, "SCANNER CHECK" is displayed on
the LCD.
(3) Press the X key and finish this operation to return the machine to the initial state of the
maintenance mode.
Note:
When printing fails, the following error indications are displayed on the LCD. When the error
factors are removed and the Mono Start key is pressed, the machine automatically
recovers to the re-executable state. "PRINTING" is displayed on the LCD, and the Laser
unit test pattern is printed on a sheet.
Error message
Replace Toner # *
Cover is Open
No Paper
Jam Tray1
Jam Rear
* # indicates the toner color (K, Y, M, or C) of which cartridge became empty.
■
Laser unit test pattern
Replace the empty toner cartridge and press the Mono Start key
to clear the error.
Close the front cover.
Load paper into the paper tray, close the paper tray, and press the
Mono Start key to clear the error.
Remove the jammed paper, close the paper tray and all the
covers, and press the Mono Start key to clear the error.
Fig. 5-16
5-48
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