Cs Led Lights-On Duration Adjustment - Canon MultiPASS C755 Service Manual

MultiPASS C755 Chapter 3: Maintenance & Service
3. ADJUSTMENT

3.1 CS LED Lights-on Duration Adjustment

a) Overview
This adjustment is used to eliminate uneven scanning which can result from variations in light intensity
between individual LED's. Performing the adjustment will therefore have an effect on scanned and
copied images.
The adjustment value is registered in an SRAM IC which has lithium battery back-up and will not be lost
even if power is turned off. However, the SRAM data can become damaged, for example by battery
depletion. In this case, the machine checks the data's validity the next time power is turned ON. If the
data is invalid, the adjustment is made automatically. Because the user is automatically prompted, it is
almost never necessary to perform this adjustment during normal use. However, if the SCNT board,
Contact sensory ass'y, or lithium battery is replaced, be sure to perform this adjustment. Also, if the color
or brightness of scanned or copied images is faulty, performing this adjustment may correct the problem.
b) Procedure
(1) Check that the operation panel is closed correctly, then perform the adjustment by following the steps
described below.
Function
Set
TEST MODE
Figure 3-2 CS LED Lights-on Duration Adjustment Operation
(2) The adjustment procedure is finished when the display reads TEST MODE.
Data registration #
2 1 2-1 ADJ LEDTIME
3-6
Display TEST MODE by
pressing or button
Several seconds later
TEST MODE