HP LaserJet 4250 Service Manual - Page 383

Paper-path checklist, Diagnostic

Page 383 highlights

■ Try printing from all of the available input trays and to all of the available output bins to identify whether the problem is isolated to one tray. ■ Print the job in both the simplex and duplex mode to identify whether the problem occurs only in one mode or the other. ■ Try printing on paper from an unopened ream that has been stored correctly. If the jam does not occur with this media, then the customer's media might be causing the problem. ■ If the jam occurs when the printer is first turned on, check the paper path for small, torn pieces of media. Also check for broken sensors or flags, and check for loose or defective connections. ■ If the media is torn, folded, or wrinkled (typically along the leading edge), inspect the paper path for items that might be causing the damage. ■ If the customer is using non-HP supplies, try replacing those supplies with genuine HP supplies to see if the problem is resolved. ■ If necessary, explain the correct methods of media storage, media loading, and printer operation to the customer. Make sure that the customer knows not to remove media from the output bin (especially during duplex printing) until it completely exits the output delivery assembly. Paper-path checklist ■ Verify that the media is correctly loaded in the input trays and that all length and width guides are set correctly. ■ Clean the printer. Toner and paper dust in the paper path can inhibit free movement of the media through the printer and can block the sensors. ■ Use the paper-path test on the Diagnostic menu to select various printer input and output options to determine if the problem is associated with a particular area of the printer. ■ Worn rollers or separation pads can cause multifeeds. Check the condition of the rollers and separation pads. ■ Defective paper-tray switches can cause jams by communicating the wrong paper size to the formatter. ■ Defective paper sensors along the paper path might signal a false jam. ■ Scraps of media that remain in the paper path can cause intermittent jams. Always check that the paper path is clear after cleaning the printer or clearing jams. Also, remove the fuser and carefully check it for debris. Paper-path test This test generates one or more test pages that can be used to isolate the cause of jams. Paper-path troubleshooting 369

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Try printing from all of the available input trays and to all of the available output bins to identify
whether the problem is isolated to one tray.
Print the job in both the simplex and duplex mode to identify whether the problem occurs only in
one mode or the other.
Try printing on paper from an unopened ream that has been stored correctly. If the jam does not
occur with this media, then the customer's media might be causing the problem.
If the jam occurs when the printer is first turned on, check the paper path for small, torn pieces of
media. Also check for broken sensors or flags, and check for loose or defective connections.
If the media is torn, folded, or wrinkled (typically along the leading edge), inspect the paper path
for items that might be causing the damage.
If the customer is using non-HP supplies, try replacing those supplies with genuine HP supplies
to see if the problem is resolved.
If necessary, explain the correct methods of media storage, media loading, and printer operation
to the customer. Make sure that the customer knows not to remove media from the output bin
(especially during duplex printing) until it completely exits the output delivery assembly.
Paper-path checklist
Verify that the media is correctly loaded in the input trays and that all length and width guides are
set correctly.
Clean the printer. Toner and paper dust in the paper path can inhibit free movement of the media
through the printer and can block the sensors.
Use the paper-path test on the
Diagnostic
menu to select various printer input and output
options to determine if the problem is associated with a particular area of the printer.
Worn rollers or separation pads can cause multifeeds. Check the condition of the rollers and
separation pads.
Defective paper-tray switches can cause jams by communicating the wrong paper size to the
formatter.
Defective paper sensors along the paper path might signal a false jam.
Scraps of media that remain in the paper path can cause intermittent jams. Always check that
the paper path is clear after cleaning the printer or clearing jams. Also, remove the fuser and
carefully check it for debris.
Paper-path test
This test generates one or more test pages that can be used to isolate the cause of jams.
Paper-path troubleshooting
369