Canon SmartBase MPC400, Service Manual

Page: 90 / 179

4-6
SmartBase MPC600F/MPC400 Chapter 4: 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 ADF or pressure plate is closed correctly, then perform the adjustment by following
the steps described below
.
(2) The adjustment procedure is finished when the display reads TEST MODE .
Figure 4-2 CS LED Lights-on Duration Adjustment Operation
Menu
Copy
Several seconds later
#
OK 2 1
2-1 ADJ LED TIME
[1]----[2]
Display TEST MODE by
pressing button
1
FOR 300 DPI CS
SERVICE MODE
TEST MODE
2 1
2-1 ADJ LED TIME
[1]----[2]
2
FOR 600 DPI CS
TEST MODE [1] - [4]
CF-FH : EC-02-01
Several seconds later