In article
s.com, JimK writes

My folks have a Laserjet 5P that will only print if fed single sheets
one at a time through the "other media" (sic) flap. I.e. if it takes
paper from the cassette underneath it will jam, but if fed manually
single sheets all is well, if infuriating!

Yes, you need the paper pickup maint kit. You might get away with just
the pickup roller, which is very easy to fit, but I'd suggest getting
the kit.

--
Mike Tomlinson