HP 8100 Tray 3 won't lift

[schmittp]

I've been fixing laser printers since there were laser printers, but haven't fixed this yet:

We have two HP 8100 (Canon WX engine) that won't lift tray 3. Tray 2 lifts ok, the printer runs fine, but the display reads 'Tray 3 empty'
It is not, the flag is not broken, the problem is tray three does not lift. I could replace the PIU (Paper Input Unit), but I have two doing the same thing, and it's probably some minor problem.

When I close tray 3, the motor runs for a while, the display says 'Tray 3 lifting', then 'Tray 3 empty.' If I close tray 3 while tray 2 is out, I can see the tray does not lift.
(It should 'jack up' in small steps, like tray 2 does. Once the pickup roller makes contact with the paper; it 'kicks' the lifting mechanism off.)

I pulled the PIU and dismantled it. I cleaned out some hair and dried grease, but it didn't help. (Didn't make things worse either.) It looks like the ratchet mechanism in not engaging the teeth on the lift. I can make it work manually when I have the PIU apart, but it will not engage when running. (There are lot of little levers in there that are complicated) The nub on the tray that releases the mechanism is intact and working. Have tried different tray 3 from a working unit, no difference.

I'm hoping someone has seen this problem, and can provide a fix for the PIUs. Refurbs are nearly $100 with shipping.

[prntrfxr]

I don't think it's good news. If this unit is in the printer, remove the trays, and use a flashlight to look where both trays went in. Compare the area of tray 2 vs tray 3. If you see a big hole on the inside of where tray 3 normally goes that is not present in the tray 2 area, you'll need a new PIU. Usually what happens is end-user gets mad and slams the tray, breaking the PIU frame in the process. The other thing that can ruin your day, is if the spring pin is broken. There's a plastic pin that has a torsion spring around it for each tray in that same area. If the pin is broken, it will be separated from the frame. Some refurb companies drive a wood screw through the pin into the frame. I refuse to do that with mine. I replace the frame. New frames are available, but changing one out takes about an hour when you know how all the gears, springs, and levers go inside. All those things have to come out when you change the frame. Which is why it costs $100+. If neither tray was lifting I would say it would probably be a sticky solenoid. But, you only have the one giving you trouble so it's bad news.

[blackcat4866]

If you've been in there, you'll know that it isn't too bad to change. I think this is the predecessor to the Canon iR330 feed unit. It looks remarkably familiar. =^..^=

[prntrfxr]

The tray 2 section is similar to the tray 3. All the metal has to come off the black plastic frame. Make sure the little arm is pushed in until it pops into place and don't forget any of the springs. The little arms inside and the cam gears inside control lift. The 6 little gears inside control roller motion. If you have another to look at as a reference it will be easy.

[schmittp]

Thanks for the replies.
I have seen one like you describe, where someone jammed the paper tray in and broke a piece out of the plastic PIU frame.


Re-inspection shows one has the plastic pin broken, but it's still there, just tilted at 45 degrees. The springs are present, but probably don't work right. Yes, it'll need a PIU frame.
At least.

The other one does not have a broken spring pin. To make sure we're talking about the same part, it is visible from the pickup roller side of the PIU, call out # 1 in drawing #2 on the page: TPW - WX Assembly Diagram 310

So, that may fix one of them, but... is there anyone who knows of a functional description, or troubleshooting charts, or something on the PIU's operation? I have the HP service manuals for this series, none have any information at all on PIU operations. I can see why people just replace them. Swapping out the PIU frame will be a major job, lots of little pieces.

If I can get one working, I can compare and maybe figure the other one out. Again, thanks to everyone for the replies, and feel free to respond further.

[prntrfxr]

No the service manual just lists the assembly. I had to learn the hard way. I've taught myself how to do the 9000 PIU, 4600/4650 PU assembly, delivery assemblies, duplex units, etc. HP doesn't provide step-by-steps on hardly anything.

[schmittp]

Well, today I picked up a used/broken LJ 5Si, which has a similar feeder, and according to Printerworks, the frame is the same part #.
Now if it just has a good PIU frame...

I'll have a go at this tomorrow, and see what happens.

Thanks again for all the help, and I'll post results as I get them.

[Helpat]

I know this is a super old thread, but it ranks at the top in Google when I search for HP Laserjet 8100 Tray 3 Empty. I decided to revive this thread so that others can benefit from what I found with my HP Laserjet 8100 printer.

I acquired an HP Laserjet 8100 from a company that used it for decades. It's an awesome workhorse, but they didn't need it anymore. It only has one problem: Tray 3 doesn't work. There is always a message that Tray 3 is empty even when it's full. And, Tray 3 Doesn't Lift when I look inside. I did some searching and found that the Paper Input Unit (PIU) is broken. However, Paper Input Units for these printers are now very hard to find. I only found one online, and the company wanted almost $500 for it. That's more than the printer is worth. It think it would be great to have a solution that allows people to continue using their current PIU.

Here is what I found with my super simple solution to the problem.

In the PIU, there is a spring that holds up a metal clip. The metal clip looks a little like a heavy paper clip that was bent. The metal clip moves a plastic bar. The plastic bar engages the tray lifting mechanism when the paper tray is inserted, or releases the mechanism when the paper tray is removed. The metal clip goes through the middle of a plastic pin and the spring is wrapped around the plastic pin. When the plastic pin breaks it slips down on the metal clip. Because the plastic pin has slipped down on the metal clip, the plastic lever that engages the lifting mechanism now hits the plastic pin and can't move.

There is a YouTube video that shows the spring that breaks when this happens. The video is only a few seconds long, and this image is all that's really needed. You can see that the spring is at a 45 degree angle to everything else because the plastic pin is broken. You can easily see if the plastic pin holding your spring is broken by removing the trays and looking inside with a flashlight.
laserjet 8100 broken spring.jpg

I disassembled my printer and discovered that the plastic pin for tray 3 could simply be removed. The metal clip and the spring still work perfectly without the plastic pin in place. I don't know if this works for tray 2, but it has worked perfectly for tray 3 on my printer.

Here are the steps I took to remove the broken plastic pin. Details about each step are outlined in the service manual, which is easy to find online. It is very important to consult the service manual for more detailed instructions.

1- I opened all doors and opened the top cover.
2- I removed both paper trays
3- I removed the toner just to keep it safe.
4- I removed the back cover
5- Removed the front cover
6- Removed the tray 1 door
7- Removed the tray 1 pickup unit
8- Removed the door and panel covering tray 2-3 paper pickup unit.
9- Removed the tray 2-3 Paper Pickup Unit.

Now, using a pair of needle nose pliers, I simply removed the metal clip. The plastic pin and spring came out with it. I removed the plastic pin from the metal clip and reinserted the metal clip and spring without the plastic pin. Everything is now working perfectly. It was an easy job and didn't take very long at all.

[CNB]

I know this is a super old thread, but it ranks at the top in Google when I search for HP Laserjet 8100 Tray 3 Empty. I decided to revive this thread so that others can benefit from what I found with my HP Laserjet 8100 printer.

I acquired an HP Laserjet 8100 from a company that used it for decades. It's an awesome workhorse, but they didn't need it anymore. It only has one problem: Tray 3 doesn't work. There is always a message that Tray 3 is empty even when it's full. And, Tray 3 Doesn't Lift when I look inside. I did some searching and found that the Paper Input Unit (PIU) is broken. However, Paper Input Units for these printers are now very hard to find. I only found one online, and the company wanted almost $500 for it. That's more than the printer is worth. It think it would be great to have a solution that allows people to continue using their current PIU.

Here is what I found with my super simple solution to the problem.

In the PIU, there is a spring that holds up a metal clip. The metal clip looks a little like a heavy paper clip that was bent. The metal clip moves a plastic bar. The plastic bar engages the tray lifting mechanism when the paper tray is inserted, or releases the mechanism when the paper tray is removed. The metal clip goes through the middle of a plastic pin and the spring is wrapped around the plastic pin. When the plastic pin breaks it slips down on the metal clip. Because the plastic pin has slipped down on the metal clip, the plastic lever that engages the lifting mechanism now hits the plastic pin and can't move.

There is a YouTube video that shows the spring that breaks when this happens. The video is only a few seconds long, and this image is all that's really needed. You can see that the spring is at a 45 degree angle to everything else because the plastic pin is broken. You can easily see if the plastic pin holding your spring is broken by removing the trays and looking inside with a flashlight.
laserjet 8100 broken spring.jpg

I disassembled my printer and discovered that the plastic pin for tray 3 could simply be removed. The metal clip and the spring still work perfectly without the plastic pin in place. I don't know if this works for tray 2, but it has worked perfectly for tray 3 on my printer.

Here are the steps I took to remove the broken plastic pin. Details about each step are outlined in the service manual, which is easy to find online. It is very important to consult the service manual for more detailed instructions.

1- I opened all doors and opened the top cover.
2- I removed both paper trays
3- I removed the toner just to keep it safe.
4- I removed the back cover
5- Removed the front cover
6- Removed the tray 1 door
7- Removed the tray 1 pickup unit
8- Removed the door and panel covering tray 2-3 paper pickup unit.
9- Removed the tray 2-3 Paper Pickup Unit.

Now, using a pair of needle nose pliers, I simply removed the metal clip. The plastic pin and spring came out with it. I removed the plastic pin from the metal clip and reinserted the metal clip and spring without the plastic pin. Everything is now working perfectly. It was an easy job and didn't take very long at all.

Is the spring you referring to the one circled in red or blue ?
Where is the metal clip you are referring to ?
I have the same problem but no bad springs from what I can tell.
The Paper Pickup Unit in the photo is just for reference and is broken from an operator slamming in tray 3 with to much force

My printer gives a notice of tray 3 lifting then stops with no movement then a notice of tray 3 empty

Thanks

Bobby

[ftl14847]

I know this is a super old thread, but it ranks at the top in Google when I search for HP Laserjet 8100 Tray 3 Empty. I decided to revive this thread so that others can benefit from what I found with my HP Laserjet 8100 printer.

I acquired an HP Laserjet 8100 from a company that used it for decades. It's an awesome workhorse, but they didn't need it anymore. It only has one problem: Tray 3 doesn't work. There is always a message that Tray 3 is empty even when it's full. And, Tray 3 Doesn't Lift when I look inside. I did some searching and found that the Paper Input Unit (PIU) is broken. However, Paper Input Units for these printers are now very hard to find. I only found one online, and the company wanted almost $500 for it. That's more than the printer is worth. It think it would be great to have a solution that allows people to continue using their current PIU.

Here is what I found with my super simple solution to the problem.

In the PIU, there is a spring that holds up a metal clip. The metal clip looks a little like a heavy paper clip that was bent. The metal clip moves a plastic bar. The plastic bar engages the tray lifting mechanism when the paper tray is inserted, or releases the mechanism when the paper tray is removed. The metal clip goes through the middle of a plastic pin and the spring is wrapped around the plastic pin. When the plastic pin breaks it slips down on the metal clip. Because the plastic pin has slipped down on the metal clip, the plastic lever that engages the lifting mechanism now hits the plastic pin and can't move.

There is a YouTube video that shows the spring that breaks when this happens. The video is only a few seconds long, and this image is all that's really needed. You can see that the spring is at a 45 degree angle to everything else because the plastic pin is broken. You can easily see if the plastic pin holding your spring is broken by removing the trays and looking inside with a flashlight.
laserjet 8100 broken spring.jpg

I disassembled my printer and discovered that the plastic pin for tray 3 could simply be removed. The metal clip and the spring still work perfectly without the plastic pin in place. I don't know if this works for tray 2, but it has worked perfectly for tray 3 on my printer.

Here are the steps I took to remove the broken plastic pin. Details about each step are outlined in the service manual, which is easy to find online. It is very important to consult the service manual for more detailed instructions.

1- I opened all doors and opened the top cover.
2- I removed both paper trays
3- I removed the toner just to keep it safe.
4- I removed the back cover
5- Removed the front cover
6- Removed the tray 1 door
7- Removed the tray 1 pickup unit
8- Removed the door and panel covering tray 2-3 paper pickup unit.
9- Removed the tray 2-3 Paper Pickup Unit.

Now, using a pair of needle nose pliers, I simply removed the metal clip. The plastic pin and spring came out with it. I removed the plastic pin from the metal clip and reinserted the metal clip and spring without the plastic pin. Everything is now working perfectly. It was an easy job and didn't take very long at all.

I have an HP 8000N looks very similar. Trays do not close I hear lifter but paper does not lift. COuld you post the site for the UTube video. Any other ideas are helpful. Thanks