Receiver Volume Adjustment (Maintenance Mode 16); Receiver Volume Adjustment - Brother MFC-8220 Service Manual

CHAPTER 7 MAINTENANCE MODE
3.8

Receiver Volume Adjustment (Maintenance mode 16)

*This is only for display, not for adjustment.
< Function >
When the handset volume is set to "HIGH", it is affected by various characteristics of the
FET (field effect transistor) on the main PCB, so the fine adjustments described below are
required. Meanwhile, the "LOW" setting is fixed and cannot be adjusted.
< Operating Procedure >
Insert the telephone cord to the line terminal (LINE) of the machine and to the
telephone jack.
Lift the handset and verify that a dial tone is heard. If the handset volume is not
appropriate, go on to the next procedure.
In the initial stage of the maintenance mode, press the 1 key and the 6 key in this
order. The present handset volume level (the default setting: "HIGH") is displayed on
the LCD as shown below.
If the volume level displayed on the LCD is the one shown below, change the setting to
the one (the default setting: "HIGH") as shown in the above (3) by using the up arrow
key and the down arrow key.
Press the Start button. The machine enters the handset volume adjustment mode,
and the PWM duty ratio is displayed at the right side of the LCD.
As hearing a dial tone from the handset, adjust the handset volume to appropriate
volume by using the 1, 3, 4, and 6 keys.
1 key: Turn up the volume by 10H.
3 key: Increase the volume by 10H.
4 key: Turn up the volume by 1H.
6 key: Increase the volume by 1H.
When the handset volume is adjusted to appropriate volume, press the Set button to
set the volume setting. Then, "PWM SETTING" is displayed on the LCD, and the
display returns to the state as shown in (3).
Press the Stop/Exit button, and the machine returns to the initial stage of the
maintenance mode.
Fig.7-7
Fig.7-8
Up arrow key
Down arrow key
Fig.7-9
7-14