sinbad
08-14-2009, 05:53 AM
Got 50 FUSER error and therefore, I installed maintenance kit in LaserJet 4 and afterward got 57 SERVICE code.
I re-installed the old fuser and still got 57 SERVICE code.
I removed fuser and turned the drive gear assembly through several revolutions by hand, and this seemed to free up the motor as follows. Before this, the motor would only run for about one second before it would hang and give 57 SERVICE. With fuser out, I powered up, depressed the rear door latch sensor and the motor ran for about five seconds -- as it would in a normal self test – but it then gave me a 50 FUSER error.
I then installed the new fuser and after waiting ten minutes, powered up. The motor ran the normal five seconds and the display read WARMING UP. It stayed in the warming up mode for a few minutes and then clicked – like a relay sound – and gave me the 50 FUSER message.
I measured the resistance across the large terminals for the fuser and got 2.2ohms on the new, and 2.5 ohms on the old fuser. Service manual says this should be “about two ohms.”
I next measured the resistance across the upper pair of small terminals for the fuser and got 248 K ohms on the new, and 236 K ohms on the old fuser. Service manual says this should be “about 220 K ohms +/- 40 K ohms.”
Do these values mean that the old fuser was probably OK?
After doing all the above, I did another power on self test and got a 57 SERVICE message – so it is going back and forth between 57 SERVICE and 50 FUSER.
For 50 FUSER persistent messages, manual says: Replace the following components in the order given: 1. Power Supply Assembly, 2. DC Controller PCA.
For 57 SERVICE message manual says:
Main Motor Functional Checks
• Inspect the gear train for debris that would block the free operation of the gears.
• Check the gears in the Toner Cartridge for wear and binding.
• Reseat J211 (or J214 on the HP LaserJet 4 Plus/4M Plus) on the DC ontroller PCA, and the main connector on the Main Motor Assembly. Refer to Figures 7-16 and 7-17 for the DC Controller PCA connector locations.
• If the problem persists, check that the +24B Voltage is present on the DC Controller. If the voltage is not present, replace the DC Controller. If the voltage is present, and the motor does not rotate, replace the Main Motor Assembly (see Figure 7-11 for location).
I have checked the gear train and it is free – i.e. the motor sometimes passes the self test, and I can rotate it by hand.
The toner cartridge is OK because it has been inserted during a successful motor self test. I powered up with the toner cartridge out and got a 50 FUSER error.
So which is the most likely culprit: Power supply, DC controller PCA, Main Motor Assembly, or other? I hate to just keep throwing parts at it until it works.
I re-installed the old fuser and still got 57 SERVICE code.
I removed fuser and turned the drive gear assembly through several revolutions by hand, and this seemed to free up the motor as follows. Before this, the motor would only run for about one second before it would hang and give 57 SERVICE. With fuser out, I powered up, depressed the rear door latch sensor and the motor ran for about five seconds -- as it would in a normal self test – but it then gave me a 50 FUSER error.
I then installed the new fuser and after waiting ten minutes, powered up. The motor ran the normal five seconds and the display read WARMING UP. It stayed in the warming up mode for a few minutes and then clicked – like a relay sound – and gave me the 50 FUSER message.
I measured the resistance across the large terminals for the fuser and got 2.2ohms on the new, and 2.5 ohms on the old fuser. Service manual says this should be “about two ohms.”
I next measured the resistance across the upper pair of small terminals for the fuser and got 248 K ohms on the new, and 236 K ohms on the old fuser. Service manual says this should be “about 220 K ohms +/- 40 K ohms.”
Do these values mean that the old fuser was probably OK?
After doing all the above, I did another power on self test and got a 57 SERVICE message – so it is going back and forth between 57 SERVICE and 50 FUSER.
For 50 FUSER persistent messages, manual says: Replace the following components in the order given: 1. Power Supply Assembly, 2. DC Controller PCA.
For 57 SERVICE message manual says:
Main Motor Functional Checks
• Inspect the gear train for debris that would block the free operation of the gears.
• Check the gears in the Toner Cartridge for wear and binding.
• Reseat J211 (or J214 on the HP LaserJet 4 Plus/4M Plus) on the DC ontroller PCA, and the main connector on the Main Motor Assembly. Refer to Figures 7-16 and 7-17 for the DC Controller PCA connector locations.
• If the problem persists, check that the +24B Voltage is present on the DC Controller. If the voltage is not present, replace the DC Controller. If the voltage is present, and the motor does not rotate, replace the Main Motor Assembly (see Figure 7-11 for location).
I have checked the gear train and it is free – i.e. the motor sometimes passes the self test, and I can rotate it by hand.
The toner cartridge is OK because it has been inserted during a successful motor self test. I powered up with the toner cartridge out and got a 50 FUSER error.
So which is the most likely culprit: Power supply, DC controller PCA, Main Motor Assembly, or other? I hate to just keep throwing parts at it until it works.