Brother HL-2600CN Service Manual page 167

3.4.2 Setting of Engine NVRAM Data
As data in the NVRAM has been preset to the optimum value at the factory, it is not
necessary to change the preset values under normal conditions. However, fine
adjustment may be required subject to the media or operational conditions.
<Purpose>
Print quality can be improved by changing the preset value in the engine NVRAM.
<Procedures of Setting>
1) Follow the procedures set out in Section 2.3 'Service Mode' in this chapter.
2) Select RAM TUNE UP mode.
3) Select the desired TUNE UP mode.
4) Adjust the preset value to the appropriate value (step).
5) Carry out a test print to confirm the print quality.
<Subject TUNE UP Mode>
Mode
LP TUNE UP
THV TUNE UP
DBV TUNE UP
CBV TUNE UP
FBV TUNE UP
Subject of Adjustment
Adjustment of laser power
Adjustment of transfer voltage
Adjustment of developer bias
Adjustment of OPC belt bias
Adjustment of cleaning roller bias
V-42
Purpose
Optical density
Transfer efficiency
Optical density
Optical density
Drum cleaning efficiency