HP Color LaserJet CM4730 Service Manual - Page 598

Table 6-8 Causes for jams in the right upper cover (continued) Cause Solution The paper loop sensors (SR13 and SR14) might be defective. 1. Make sure that the sensor levers move smoothly. 2. Run the component test. 3. Replace the sensor if it is defective. The DC controller PCB is defective. 1. Upgrade the DC controller firmware by using the RFU process. 2. Replace the DC controller PCB. Calibrate the MFP after replacing the DC controller. See Calibrate the MFP on page 604. Jams in the duplex path The following table describes the causes of and solution for jams in the duplex path. Table 6-9 Causes for jams in the duplex path Cause Solution The oblique rollers are worn or damaged. Replace the ETB. The oblique roller drive gears are worn or damaged. Replace the ETB. Calibrate the MFP after replacing the ETB. See Calibrate the MFP on page 604. The duplex feed guide is damaged. Replace the ETB. Calibrate the MFP after replacing the ETB. See Calibrate the MFP on page 604. The reversing sensor (SR8001) or the sensor lever is defective. 1. Run the component test. 2. Replace the duplexer assembly if it is defective. The duplexer connector is unplugged or not seated properly. Reseat the connector. Jams in the ADF Table 6-10 Causes of jams in the ADF Cause Solution The clear mylar sheet in the ADF might be installed incorrectly. Make sure that all four alignment holes on the mylar sheet are secured over the tabs. The small notch on the sheet should be aligned with the round pin at the top of the mylar sheet holder. See the instructions that came with the mylar sheet replacement kit. The ADF pickup roller assembly might be installed incorrectly. Make sure the roller assembly is correctly seated and that the paper-present flag and the registration flag can move freely. 578 Chapter 6 Problem solving ENWW