A customer with a HP LaserJet M375nw multi-function printer was having paper-feed issues with the automatic document feeder which passes A4 sheets through the scanner.
They replaced the 5851-3580 ADF Pickup Load Arm and Bogey (which contains the ADF paper pickup rollers), but this did not improve ADF scanning.
Further examination identified that the rollers on the underside of the ADF unit (CE863-60101 / CE863-60106) were worn. These rollers pull the sheet back into the unit when duplex (double-sided) scanning (in practice the page makes five passes past these rollers – scan first side, retract, flip page over, retract, scan second side).
As our customer could not find these lower rollers in the HP parts documentation, they contacted us for help.
The HP service manual for the M375/M475 lists two document feeder assemblies: simplex and duplex (unfortunately the labelling in the parts table does not match the accompanying diagram).
However as both the M375 and M475 perform duplex scanning, it is not evident why there are two different assemblies (CE863-60106 and CE863-60101) – the HP brochure describes both printers as having identical scanning capabilities.
Consulting HP partsurfer (http://partsurfer.hp.com/) it turns out that Part CE863-60106 is no longer supplied. Please order the replacement, CE863-60101
Looking at a similar assembly (Q3948-67903), the lower reversing rollers are not designed to be easily replaced, which is presumably why they are not available for separate purchase. Perhaps given the intended duty cycle (500 – 2,500 monthly pages) of the various HP printer models that use this ADF unit, these scanner rollers are not expected to need replacing in the lifetime of the printer?
So our customer’s options are either to replace the entire ADF assembly, or try a roller restorer on the worn rollers.
Determining the above took quite a few hours, without a guaranteed final sale to recoup the time spent.
This sort of investigation is not untypical – ad-hoc queries which often do not result in a sale.