TROUBLESHOOTING GUIDE
17 January, 2003
4-60
4.4.3 COLOR SHIFT AFTER TRANSFER UNIT REPLACEMENT
If the color shift level is not within the target range (max 180
µ
m) after replacing the
transfer unit and performing the forced line position adjustment (SP5-993-002 or
‘Auto Adjust’ in User Program Mode), follow the procedure explained below.
Check the color shift level
1. Make sure that OPC Refresh (SP3-920-005) has been done.
2. Print out the SMC sheets (SP5-990-002).
3. Print a 1-dot grid pattern using A3/11" x 17" paper. Refer to the following table
for detailed SP mode settings.
SP5-997 (Test Pattern) Setting
Mode
Tray
selection
Pattern Color
mode Resolution
Paper size
(By-pass)
Normal, color, 600 dpi
2
05
Full Color
600x600
—
Normal, color, 1200 dpi
2
05
Full Color
1200x1200
—
NOTE:
Any adjustment needs to be done by using the paper type which the
customer normally uses.
4. Check the tendency of color shift in the grid pattern printed in step 3.
Sometimes, a magnification scope must be used to measure the amount of
color shift between colors.
5. If the result is not within the target, go to the next step.
Fusing/ Registration Roller Speed Adjustment
SP mode (sub-scan registration) reset
1. Make sure that the SMC sheets (SP5-990-002) have been printed out.
2. Reset the setting of SP5-993-016 to 021 to “0”.
Transfer belt aging
1. Remove all PCUs. Place them on clean sheets of paper and cover the drums
with a few sheets of paper to prevent the drums from light fatigue. Then, secure
the drum positioning plate (2 screws) and return the transfer unit release lever
to the original position.
2. Perform the transfer belt idling with SP5-804-074 (Drum M H CW) for about 3
minutes. (This is to stabilize the transfer belt side-to-side movement.)
3. Reinstall the PCUs.
4. Perform the line position adjustment (SP5-993-002 or ‘Auto Adjust’ in User
Program mode).
5. Print a 1-dot grid pattern using A3/11" x 17" paper in 600 dpi mode.
6. If the color shift in the main-scan direction is not within the adjustment standard,
follow the troubleshooting guide.