Brother International HL-2400C Service Manual - Page 161

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. Print quality can be improved by changing the preset value in the engine NVRAM. 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. Mode Subject of Adjustment LP TUNE UP Adjustment of laser power THV TUNE UP Adjustment of transfer voltage DBV TUNE UP Adjustment of developer bias CBV TUNE UP Adjustment of OPC belt bias FBV TUNE UP Adjustment of cleaning roller bias Purpose Optical density Transfer efficiency Optical density Optical density Drum cleaning efficiency V-40