HP 4550 Service Manual - Page 233

Table 7-3 Numerical printer error messages (continued)
To turn off Lossy mode once the file has printed, use the following commands: ESC%-12345X@PJL @PJL Default Diagnostics=OFF @JPL Default Service Mode=EXIT @PJL EOJ ESC%-12345X@PJL Note Putting the printer in Lossy mode might affect performance and print quality 49 FFFF Description: Action: Issue reported by life test when replacing the fuser. Replace the formatter. This error might also occur during the boot cycle. 49FFOX Description: This error message allows you to scroll through the printer control panel to obtain all of the error information. Action: No action required. 49 OBOA Description: A request is not understood. This error message is generated when the I/O card does not support a command that was sent to it. Action: Check the command being sent; the I/O card might not support a particular feature. 49 OB22 Description: Action: This error message is generated when the I/O card Verify the action being sent. receives a control panel menu action that it does not recognize. 50.x Fuser Error Description: Action: The fusing assembly contains two heating bulbs, two thermo-switches, and two thermistors. AC power is provided to the fusing assembly via the DC power Note supply, which is controlled by the DC controller PCB. The thermistors monitor the temperature of the fusing assembly and provide feedback to the DC controller PCB to regulate the fusing temperature. The two thermo-switches are wired in series with the fusing bulbs, and "open" if the temperature exceeds 240° C (464° F). To visually check if the fusing assembly is functional, you can defeat the rear door interlock switch (see Figure 7-33). Press in on the white plastic above the left rear corner of the fan, then turn on the printer. If the fusing bulbs and thermo-switches are good, you should observe light from the lower fusing bulb as the printer warms up. X Description: 1 Low temperature error 2 Fuser warm-up service 3 High fuser temperature 4 Faulty fuser 5 Fuser voltage mismatch (verify that you have NOT installed a 110V fuser in a 220V printer or vice-versa). 6 Fuser heater cutoff 7 Fuser motor malfunction (see recommended action for 50.7 Fuser error) 1. Turn the printer off and on to reset the printer. If the error persists, try re-installing the fusing assembly. If the error continues to persist, proceed to step 2. 2. Turn the power off and remove the fusing assembly. Measure the resistance between pin 3 and pin 4. The resistance should be between 6+/-2 ohms. If there is no continuity between pins, it can be assumed that either a heating bulb and/or a thermo-switch is "open." Replace the fusing assembly. If resistance limits are acceptable, proceed to step 3. (Continued on next page) C7085-90921 Chapter 7 Troubleshooting 231