HP Color LaserJet Enterprise CM4540 Service Manual - Page 670

Problem Some color is misregistered. Sample Toner smears appear on the media. The printed page contains misformed characters. Text or graphics are skewed on the printed page. Cause The product is incorrectly calibrated. The ITB unit is defective. The drive gear of the ITB motor is worn or chipped. The RD sensor is defective. The laser/scanner unit is defective. The print cartridge is defective. The product has residual media. The fuser inlet guide is dirty. Solution Calibrate the product. If the ITB does not rotate smoothly or a cleaning malfunction occurs (ITB is dirty), replace the ITB. See Intermediate transfer belt (ITB) on page 120. Check each drive gear between the ITB drive roller and the ITB motor. If the gear is worn or chipped, replace the drive unit. Open and close the front door several times to clean the RD sensor. If the problem persists, replace the RD sensor. See Registration density (RD) sensor assembly on page 209. Replace the laser/scanner assembly. See Laser/scanner assembly (Y/M) on page 275 or Laser/scanner assembly (C/Bk) on page 279. Replace the print cartridge of the affected color. Remove the residual media. Clean the fuser inlet guide. The product is experiencing page skew. See the "Text or graphics are skewed on the printed page" row in this table. The laser/scanner unit is defective. Replace the laser/scanner assembly. See Laser/scanner assembly (Y/M) on page 275 or Laser/scanner assembly (C/Bk) on page 279. The registration shutter spring Check the spring and place it in the is unhooked. correct position. The registration shutter spring is deformed. Replace the secondary transfer assembly. See Secondary transfer assembly on page 204. 618 Chapter 3 Solve problems ENWW