2024-06-28 - Fixing an HP Color LaserJet 2820 That Only Prints Blank Pages -------------------------------------------------------------------------- I recently got an HP Color LaserJet 2820[0] that was only printing blank pages. Luckily, other people already had the same issue, so I eventually managed to find various forum posts describing what needed to be done. This article is meant to document everything I did, in case it's useful for anyone else, especially since I could only find vague descriptions of the fix, no proper guide. I won't describe how to actually take the printer apart because that's covered in the service manual[1] (downloaded from [2]). Note that the LaserJet 2820 is very similar to the LaserJet 2840, so all of this probably also applies to the 2840 (many of the forum posts I found were actually for the 2840). WARNING: Always unplug the printer completely before working on it. Please don't die from an electric shock. WARNING: Toner is apparently pretty unhealthy to breathe in, so you might get lung cancer and die if you follow these instructions without protecting yourself properly. Misaligned Carousel Gears ------------------------- The first issue is that the carousel in the middle which holds the toner cartridges can get misaligned. This was not the main issue with my printer, but the carousel still was misaligned. [3] is a good video showing how to align the gears without having to take the entire printer apart. First, you need to release the carousel brake by sticking something into the hole shown in [4] so the brake is pushed up. The wire I used wasn't really ideal, but it worked well enough. The carousel can then be moved by hand in order to remove all toner cartridges. After that's done, the gears on both sides need to be aligned. The alignment marks on the large black gears need to be between the two marks sticking out of the white gears, as shown in [5]. The black gears can be pushed inwards until it's possible to move them independently of the white gears. The proper method would be to take the printer apart completely so you don't need to use as much brute force and risk breaking the gears, but this method still seems to work fine. The black gear on the left can be accessed more easily than the one on the right but is still more annoying to align because it is much thicker, so it needs to be pushed in more before it can be moved independently of the white gear. This was the first fix I performed on the printer, but the printed pages were still blank afterwards. Sticky Solenoids ---------------- The main problem with the printer was the solenoid switch used to brake the carousel. Over time, the soft pad on the switch turns into a sticky residue that makes the brake release with a slight delay. This seems to be a common problem[6][7][8]. The first step to fix this is to follow the instructions for removing the right support assembly on page 174 of the service manual (a lot of other parts need to be removed first, before the actual support assembly can be removed, as shown in the manual). Note that the instructions forgot one screw, shown in [9]. The printer I have seems to be very slightly different than what is shown in the images there. I don't entirely remember if I had to remove anything else here, but I think this is all that needs to be removed. Once the assembly has been removed, the metal piece above the solenoid has to be removed[10]. In order to remove the solenoid itself, the motor needs to be removed because the screw on the solenoid cannot be accessed properly otherwise (at least with a straight screwdriver)[11]. After the motor has been removed[12], the solenoid can be removed[13]. As can be seen, the padding material has become completely sticky. [14] shows the delayed release of the switch. I first cleaned the old residue with isopropyl alcohol, then stuck on a new pad. I didn't really have any proper felt material, so I used a piece of strong double-sided tape and stuck some cloth on one side[15]. [16] shows the fixed solenoid. One important note here is that it is crucial to remember which screws go where. This is always important, of course, but here there are screws that look very similar but have different lengths[17]. If one of the longer screws is used to screw the solenoid back in, it will push on the gear that is located on the other side of the metal frame. There is another solenoid in the printer (apparently, this one controls the paper pickup in tray 1). This one wasn't causing any problems yet in my printer, but it's probably a good idea to fix it as well while you're at it. In order to access the solenoid, first follow the instructions for removing the gear assembly on page 192 of the service manual. The main part is removing the right support assembly, so it's a good idea to fix this solenoid directly after fixing the other one to avoid duplicated work. The solenoid is covered by a metal cage which needs to be removed first[18]. The problem is that the cage is obstructed by a lot of cables that have barely any slack. I ended up moving the cables out from the two guides one or two at a time using a hook since there wasn't enough slack to move them all out at once[19]. There's probably a better method, but this method worked (although it took a while). After that, the metal cage can be removed, and the solenoid can be accessed[20]. The rest of the repair is the same as for the other solenoid. Cartridge Problems ------------------ Once the solenoids had been fixed, the printer actually started printing, but the quality was still pretty bad. There were many streaks on the printed pages, in particular large yellow streaks and a magenta streak on one side[21]. I determined that this was caused by the cartridges having toner applied unevenly on their rollers[22]. I wiped the rollers down in order to remove the build-up of toner, and even took the magenta cartridge apart[23] because a lot of toner had collected on one side. I'm guessing that this printer hadn't been used for a long time and maybe also wasn't transported very carefully. Problems with the Drum Assembly ------------------------------- Note: I ended up buying a new drum assembly, so this section is only included in case anyone else can learn something from it. After fixing the toner cartridges, the yellow and magenta streaks went away, but there still were streaks all over the page[24]. If I cleaned the drum manually, the first page afterwards would be slightly better, but then it would be the same as before again. I assumed that there was something wrong with the wiper blade that cleans the drum, so I decided to take the drum assembly apart. Unfortunately, I accidentally broke the protective cover off while messing around with the assembly[25]. First, the screws on both sides need to be unscrewed and the side covers removed. WARNING: Some gears easily fall out when these covers are gone. It's probably a good idea to tape them down so nothing happens. I didn't do this, which caused problems later. There are two covers over the transfer belt that need to be removed from the assembly. [26] can be removed by turning the plastic wheel. [27] can be removed by unscrewing two screws. Note the hard drive magnets on my screwdriver to make it more magnetic. The smaller assembly containing the actual drum can then be removed by pulling out one of the metal rods connecting it to the rest of the larger assembly[28]. This is a good oppertunity to clean the transfer belt because a large area of it is exposed[29]. Note that it apparently isn't good to leave the drum or transfer belt in the light for too long, so ideally cover them when you're not working on them. The assembly containing the drum can then be opened up by unscrewing the metal pieces on the sides. Unfortunately, one of the metal pieces is additionally fastened using a plastic piece[30] that has to be broken to remove it[31]. The top cover on this assembly also needs to be removed by unscrewing two screws[32]. The drum can then be removed from the assembly, although it takes a bit of fiddling around to do that[33]. The wiper blade can then finally be accessed[34] and removed from the assembly[35]. As can be seen, it was very dirty, so I cleaned it using isopropyl alcohol. Isopropyl may not be ideal for rubber, but it was impossible to clean off the hardened toner otherwise. I also emptied the waste toner tank behind the wiper blade which contained a lot of toner. After reassembling everything, the printer gave me an error with the code 59.99. According to the service manual, this means "T2 clutch error". I wasn't really sure at first what that meant. This is also the point at which I fixed the paper tray solenoid because some forum posts claimed the error was related to that (I guess the code means something different in other printer models). I then remembered that I read somewhere that the wiper blade needs to be "oiled" using toner so it doesn't completely block the drum movement. With that knowledge, the error description makes sense because the drum probably couldn't be moved properly, causing the clutch to fail. After re-adding some toner to the wiper blade, the printer started printing again, but part of the page was blank, and the quality of the other part wasn't better than before. This is when I noticed that I had made a mistake when putting one of the gears back in that had fallen out (which is why you should tape the gears down when taking apart the drum assembly). One of the gears is connected to a plastic rod that goes through to the other side of the assembly[36]. This moves two black gears, one on each side, which are responsible for lifting a roller away from the transfer belt (I'm not sure what exactly this roller does, maybe it cleans the remaining toner from the belt)[37]. The plastic rod needs to connect the two sides in such a way that the roller is lifted on both sides at the same time. When part of the page was blank, I had actually not connected the rod properly at all, so the gear on one side wasn't turning. It's a pain to connect the rod properly, so, again, just tape down all the gears. I also am not sure if the gear connecting to the rod was aligned properly with the other gears in the mechanism since there weren't any alignment marks. After all of this, the printer printed again, but the quality wasn't any better than before. Maybe I should have cleaned the wiper blade differently (some sites also suggest that the "oiling" should be done using yellow toner because it's finer), but I finally decided that it would be better to just get a new drum assembly. IT WORKS!!!!! ------------- I managed to find a new drum assembly on eBay for 26.90€. When that arrived, the printer finally printed properly without any streaks. I also noticed that the new drum was clean after printing[38], so the problem on the old assembly was almost certainly related to the wiper blade. As suggested by johnny_b on libera.chat, I used the fixed printer to print a very appropriate poster[39]. Conclusion/Philosophical Ramblings ---------------------------------- One question now remains: Was it really worth it? Financially, it definitely wasn't worth it because I spent many hours working on the printer and also had to buy the new drum assembly, while it's possible to get decent used printers for next to nothing. I think it still was worth it mainly because of everything I learned through the repair. However, I think this is actually the wrong question to ask. The right question isn't "was it worth it?", but rather "should it have been worth it?". The reason why it wasn't (financially) worth it is that we as a society don't value old equipment and the environment enough. This printer is an amazing, complex device that can now be used again without any problems. Still, most people would have just thrown it away, generating more electronic waste of which only some parts are actually recycled. That's the way it currently is, but it's not the way it should be. So, in conclusion, even if perhaps this whole endeavor really wasn't worth it, it definitely should have been. [0] gopher://lumidify.org/I/phlog/2024-06-28-printer/printer.jpg [1] gopher://lumidify.org/9/phlog/2024-06-28-printer/hp_laserjet_2820_service_manual.pdf [2] https://elektrotanya.com/hp_laserjet-2820_2830_2840_sm.pdf/download.html [3] https://youtube.com/watch?v=xKwsYipQ0Ag [4] gopher://lumidify.org/I/phlog/2024-06-28-printer/brake_release.jpg [5] gopher://lumidify.org/I/phlog/2024-06-28-printer/gear_alignment.jpg [6] https://joeabaya.com/index.php/2018/02/14/hp-2840-carousel-brake-solenoid-repair/ [7] https://h30434.www3.hp.com/t5/LaserJet-Printing/hp-color-laserjet-2840-printing-and-copy-blank-page/m-p/5590198/ [8] https://h30434.www3.hp.com/t5/LaserJet-Printing/LaserJet-2840-Colour-printing-issues/m-p/7938578 [9] gopher://lumidify.org/I/phlog/2024-06-28-printer/missing_screw.jpg [10] gopher://lumidify.org/I/phlog/2024-06-28-printer/piece_above_solenoid.jpg [11] gopher://lumidify.org/I/phlog/2024-06-28-printer/motor_obstruction.jpg [12] gopher://lumidify.org/I/phlog/2024-06-28-printer/motor_missing.jpg [13] gopher://lumidify.org/I/phlog/2024-06-28-printer/solenoid_sticky.jpg [14] gopher://lumidify.org/9/phlog/2024-06-28-printer/solenoid_sticky.ogv [15] gopher://lumidify.org/I/phlog/2024-06-28-printer/solenoid_new_pad.jpg [16] gopher://lumidify.org/I/phlog/2024-06-28-printer/solenoid_fixed.jpg [17] gopher://lumidify.org/I/phlog/2024-06-28-printer/screw_length.jpg [18] gopher://lumidify.org/I/phlog/2024-06-28-printer/tray_solenoid.jpg [19] gopher://lumidify.org/I/phlog/2024-06-28-printer/tray_solenoid_cables.jpg [20] gopher://lumidify.org/I/phlog/2024-06-28-printer/tray_solenoid_uncovered.jpg [21] gopher://lumidify.org/I/phlog/2024-06-28-printer/cartridge_streaks.jpg [22] gopher://lumidify.org/I/phlog/2024-06-28-printer/cartridge_bad.jpg [23] gopher://lumidify.org/I/phlog/2024-06-28-printer/cartridge_open.jpg [24] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_streaks.jpg [25] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_cover_broken.jpg [26] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_cover1.jpg [27] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_cover2.jpg [28] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_metal_rod.jpg [29] gopher://lumidify.org/I/phlog/2024-06-28-printer/transfer_belt.jpg [30] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_plastic_fastener.jpg [31] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_plastic_fastener_broken.jpg [32] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_top_cover.jpg [33] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_open.jpg [34] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_wiper_blade.jpg [35] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_wiper_blade_outside.jpg [36] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_connecting_rod.jpg [37] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_gears.jpg [38] gopher://lumidify.org/I/phlog/2024-06-28-printer/drum_new.jpg [39] gopher://lumidify.org/I/phlog/2024-06-28-printer/manifesto.jpg