Table |
| 50 SERVICE Fuser Malfunction Checks | |
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| Checks | Action | |
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Is the Fuser Assembly correctly | Reseat the Fuser Assembly. Allow | ||
seated? |
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| adequate time for the error message to |
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| clear (10 minutes) and turn the printer |
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| ON. |
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Is the Fuser Bulb/ Thermoswitch open? | The fuser bulb and thermoswitch are | ||
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| wired in series. To check if one or the |
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| other is defective, perform the following: |
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| 1. Remove the Fuser Assembly from the |
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| printer. |
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| 2. Use an ohmmeter and measure the |
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| continuity between pins (see Figure |
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| |
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| ohms (about 4 ohms for the 220 volt |
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| fuser). If an open condition is detected, |
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| either the fusing bulb or the |
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| thermoswitch is defective. Replace the |
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| defective component (refer to Chapter |
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| 6) or replace the complete Fuser |
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| Assembly. |
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Is the Thermistor defective? | 1. Remove the Fuser Assembly and let it | ||
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| cool to room temperature. |
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| 2. Use an ohmmeter and measure the |
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| resistance between pins (see Figure |
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| K ohms +/- 40 K ohms at ambient |
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| room temperature. If the thermistor is |
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| either open or shorted, replace the |
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| thermistor (refer to Chapter 6) or the |
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| complete Fuser Assembly. |
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Does the error persist? | 1. Verify all cabling is correct. | ||
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| 2. Replace the following components in |
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| the order given: |
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| Power Supply Assembly |
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| DC Controller PCA |
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See Figure
N o t e | The 50 SERVICE error message can be cleared |
| immediately by shorting the C202 leads on the |
| HP LaserJet 4/4M (or the C205 leads on the HP |
| LaserJet 4 Plus/4M Plus/5/5M/5N) on the DC |
| Controller. Remove the Formatter PCA to access |
| the DC Controller as shown in Chapter 6. |