量一下两点间的距离，是否是不变的。如果是不变则看下表
Table 1 Repeating Defects
Repetition spacing
Component(s)
Repair Actions
<4 MM.
High Frequency Banding
95 MM.
Photoreceptor
Single Color - Replace the Drum Cartridge (see CRUs and Consumables in Section 6).
38 MM.
BCR
56 MM.
Developer Mag Roll
Check Developer roll bias for floating or shorting out. Replace Developer Housing (PL 5.2) if required.
84 MM.
Fuser Heat Roll
Ensure correct paper type is set for the actual paper in the paper tray. Remove the Fuser Assembly. Check the Heat Roll for damage (nicks, wear, or cuts) or contamination. Clean or replace as required (PL 7.1).
94 MM.
Fuser Pressure Belt
All Colors - Remove the Fuser Assembly. Check the Heat Roll for damage (nicks, wear, or cuts) or contamination. Clean or replace as required (PL 7.1).
25mm
BTR 1 Roll
55 MM.
BTR 2 Backup Roll
BTR 2 Roll
Check the 2nd BTR Assembly for damage or contamination. Clean, repair or replace as required.
Replace