HP 8550mfp Service Manual - Page 393

Table 42. Unnumbered printer messages (continued) CLEAR INPUT DEVICE JAM (continued) Event log message: 13.11.2 Description: 1 = Page stays too long at paper entry sensor (PS31) B = Page stays too long at paper exit sensor (PS32) Action: 1 Open the VTU and remove any media. 2 Verify that the paper entry sensor (PS31) moves freely. 3 Verify that the feed, separation, and pickup rollers are properly seated. 4 If the problem persists, open the VTU and override the VTU closed sensor (PS35). Perform a paper path test feeding from the 2,000-sheet input unit, and verify that the feed rollers are advancing the paper. If rollers do not rotate, verify the connections at the pickup assembly and the controller PCA in the 2,000sheet input unit. 5 If the rollers rotate and drop down but do not advance the paper, replace the feed and separation rollers using the maintenance kit. 6 If the rollers do not rotate or do not drop down, replace the pickup assembly. 7 If the problem persists, replace the VTU, which includes PS31. Event log message: 13.11.3 Description: 1 = At power on, paper entry sensor (PS31) in VTU is active B = At power on, paper exit sensor (PS32) in VTU is active Action: 1 Open the VTU and remove any media. 2 Verify that PS31 and PS32 in the VTU move freely. 3 If either PS31 or PS32 are damaged, replace the VTU. EN Printer message troubleshooting 391