hp laserjet 1020 multiple paper feed

[mind_boggler]

Thanks dmkllkmd! Had this exact problem with my LaserJet 1012. I replaced the separation pad (which didn't help) and was about to throw my printer away. Cleaned the solenoid and voilá!

[WolverineXii]

I also had the same problem. Whether I printed one page or multiple pages, my Laserjet1020 would print the first page fine but subsequently pickup an unnecessary extra page, causing a paper jam with the extra paper. I tried cleaning the pickup roller to no avail. Then cleansed the separation pad but it didn't solve anything either. I was about to purchase a new separation pad and was about to just throw away my printer for a new one when I found this forum.

Thank you SoundinSteve for posting the solenoid solution! And thank you Dmkllkmd for describing what you did!

The solenoid is an electric magnet found on the side of the printer. HP stuck a bit of padding material in between the metal plates of the solenoid so it doesn't make noise when printing. But over time the padding material wears out and turns into a sticky residue and causes the metal plate to stick for milliseconds too long (triggering the printer to subsequently pick up an unneccessary extra page, resulting in jams). Just remove the residue with a QTip or cover the sticky residue with a little scotch tape and the solenoid is back to functioning properly! No need to mess with the spring and risk breaking it off.

Laserjet 1020's sideYou just need to undo this one screw on the back to take the side cover off.Fiddle and pop off the side cover.This is what the interior looks like.This is the solenoid (an electric magnet). The black screw on top of it is the only screw you'll need to undo to take the solenoid out.I'm using a screwdriver to show the metal plate being held down (which is what it'll look like when the electric magnet is engaged.This is when the magnet isn't engaged. The solution is to remove the solenoid and take a qtip and wipe off the sticky adhesive residue until the metal plate no longer sticks. The sticking is what causes the printer to feed an unnecessary subsequent page, causing jams. You can also just cover the residue with scotch tape and it does the trick!

[richardurban]

I have an HP LaserJet 1300 with the same problem of the sticky dissolved tape on the solenoid causing multiple sheets to feed and jam.
However, when I removed the sticky tape, the solenoid still stuck.  I then bent the tab that the spring attaches to down (to stretch the spring more).  I also put a piece of electrical tape around the metal piece that the spring pulls on toward the end where the tab is that engages the gear.  

I think that part of the problem may be that there could be some magnetic force transferred to the small metal piece that moves that is on top of the solenoid, which caused it to stick after removing the residue.

In any case, it works now.