HP laserjet 3390, 3392 all-in-one Manuale Di Servizio

Media passes between the heating element and a soft pressure roller to fuse toner to the media.

1.

Unplug the all-in-one for at least ten minutes.

2.

Verify that the thermistor connector is seated into both the all-in-one chassis and the ECU.

3.

Remove the heating element connector from the ECU. To measure the continuity of the heating
element, measure the resistance between the two pins at the end of the cable.

Normal resistance is 25 ohms +/- 10 ohms for the 110 V all-in-one and 80 ohms

+/- 20 ohms for the 220 V all-in-one.

If no resistance is measured, replace the fuser.

4.

Remove the thermistor connector, and then measure the resistance between J206 pins one and
two and between J206 pins three and four.

 Normal resistance between both pairs of pins is 370K ohms +/- 50K ohms at 20°

C (68°F).

5.

If no resistance is measured, replace the fuser.

The high-voltage contacts in the all-in-one must have a good connection with the contacts on the print
cartridge to provide the necessary voltages for the electrophotographic processes.

Remove the print cartridge and visually inspect the three connection points on the ends of the print
cartridge: drum ground (callout 1), charging (callout 2), and developing roller (callout 3). If they are dirty
or corroded, clean the connection. If they are damaged, replace the print cartridge.

Use only isopropyl alcohol to clean the connections.

ENWW

Functional checks

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