Many Thanks for an excellent procedure. I would never have been able to disassemble the thing, let alone fix it, without your guidance. Thanks to you my 25 year old HP 4L is back in business and I only had one screw left over.
As I sit here in disbelief...this worked great. It took less than an hour and I wrote down every step of the way so I could easily go back and reassemble. The hardest step was putting the bottom tray back on...the two white connectors and the black ones didn't quite want to go back in. All I needed was a screw driver, a couple q-tips, some goof off and a very small flat-head screwdriver for the plastic clip part. I'll take this laser printer over any of the inkjets out there. Thanks!!!
Added my two cents, I too hate putting good machines out to pasture before their time. Your video was excellent, cleaned the solenoids as advise and printer is behaving like new. BTW my envelope print function wasn't working prior to repair - it is now!! Thank you!
Yes, this tutorial does help to fix the printer. I found the second solenoid much later. I'm wondering where the sticky brown cream is coming from. That solenoid does couple the black front-side O-roller to the gear and is responsible for both envelope feed and paper-tray feed. When it sticks for some 1/10 second, the printer stops showing paper jam message.
Brilliant -thanks - this also works for a LaserJet 4MP - it's very similar except to remove the bottom plate part you also need to unscrew the rear piece where flat feeds come out and the mains on/off switch chunk. That means you then don't need to force apart the metal plate & circuit board from the body - it just lifts out. But keep your concentration up! I also have 2 screws left over and the paper tray is a struggle to get in .. but it keeps my 21 yr old printer working - ink jets, pah..
Excellent video. It took me 2.5 hours to do it; both solenoids needed cleaning. I used alcohol, Q tips, and a dental pick to clean the solenoids in place. I had a couple of difficulties on reassembly. The paper sensor arm fell out when I turned over the printer during disassembly (it's in loose) and I had to figure out where to put it back, without much help from the low-contrast photos in the HP 4L service manual. When reinstalling the D roller, I thought it might be important to get it back in exactly the position it was on disassembly, where the solenoid arm could be tucked behind it by rocking the D roller slightly. I used Brent Rasmussen's method for getting the main board back in place; that made it much easier. Thanks for the video and for the explanatory comments below. Roger
Thank you! I followed your instructions and it was that first solenoid that was sticking badly. Used goo gone to remove the residue and it is now printing like a charm! The printer had been on a shelf for a few years and initially printed well when I put it back in service, but it choked during a longer job (probably heated up just enough to gum up the residue) and it would jam just past the point where the paper was pulled from the tray. Putting it back together was hard, but I got it!
Thanks to your excellent guide I have just resurrected my 1993 Laserjet 4P :-). My paper jam issue had been gradually getting worse until finally it would not feed at all. I had assumed that it was the rubber rollers that had failed, I would never have thought that the solenoids were sticking. The 4P is very similar to the 4L but I had to remove a few more parts to gain access to the solenoids. I had to remove the fusion roller from the rear and the power switch assembly from the side. I had 3 screws left over toward the end of reassembly. I then remembered that there were 2 underneath the controller board and one recessed down a deep hole behind the mains switch assembly. Watch out for the small (3cm long) black plastic piece that sits with its axle in 2 notches when removing the lower metal cover and main PCB assembly.
Thanks a million! This is the second time I have fixed this printer, thanks to your video. Brent's suggestion makes it very easy, so make sure to do it. Besides the sticking solenoid, my black roller in the roller assembly was also worn. I put it back together, taking care to place the D roller in the same position as it was when I took it apart, but it still did not work. I had read somewhere else that one can brush some white glue onto the worn roller, and that would help. Took it apart again, put the glue on, and lo and behold, now it's working. Thanks all! I love that printer and hate adding to the waste on the planet. Had it since the 90's....
Thanks a lot! I had the same problem. I recommend to take note of the comments below: remove the rear directional paper assembly (Brent Rasmussen), and in case part RB1-2970 N 3/4 falls out: it fits close to the D-roller, near the edge of the device.
Thanks for instructions, it shows steps very well, missing one or to pictures/steps, but those not crucial! No screws leftover ;) Unfortunaly my problem remains. The other solution is to try to make better grip of black roler either by benzin or maybe with sandpaper. Black roler near D roler is very smooth/sleapery. Btw my problem is the paper got stuck on first draw/page everytime, nothing is printed. This is happening after one time it draw many paper one time, maybe 20pages,and it got stuck.
Great tutorial! The problem started slowly with my printer. It would jam every 5 or 6 pages until eventually it would only printer every other page. Cleaning the solenoid assemblies did the trick! My 20+ year old HP 4L lives on!
Thank U soooo muuch. My printer was in my garaje 4 years and now it´s working perfect cleaning that stick thing. 1994 model, 20 years!! I also sand the foam roller and followed the Brent tip for the white conectors. Gracias desde España!!
The fuser should have been taken off the back end (3 screws and pull out) first. Then when you get to 2min47sec those 2 white plugs would not be there. A lot easier and then put the fuser back in last. But this is the best video I have seen for the HP4L to replace the Controller Board.
Thanks for the detailed video. I need to change my Pickup Feed Roller. Presumably the procedure is similar to what you have described, or is there an easier method to just change the D Roller
haven't even tried it yet but i have everyone hope it will work. the video is beaut. clear, calm, not confusing. he makes good videos. good man. thanks a lot. my 4L might live on... :) they don't make 'em like that any more, I think?
Note for minute 4:22: This screw is not necessary to remove. (At least for me.) Note for minute 4:50: The D roller prevents you from easy access to the screw. However, when you unscrew the metal sheet with the many cogwheels from the side, you can easily rotate the D roller away. I prefer this method. The cogwheels are not indexed, so it's allowed to assemble them in any rotational position. May I add subtitles to your helpful video?
Great video - I love these printers.. Having looked around my printer a few times I found that I can clean one of the solenoids without disassembling. Take the paper tray out and look for a hole at the front of the printer next to the D roller. You can see a 10 pin socket inside. From this hole you can get a Q tip in to clean the sticky stuff off. Fixed it for me :) #NoDisassemble
To get the main board re-installed correctly: In the back, remove the screws that hold the rear directional paper assembly, and pull the assembly out. The two white connectors will come with it. Install the main board, properly seating the two black connectors, then re-install the rear directional paper assembly, which will connect the two white connectors to the main board properly. If you don't take the rear assembly out, you will almost always screw up the two black connectors on the main board.
Great video very helpful... but I need help, on releasing the main cct board a plastic part fell out from somewhere. It is a molded and is about 2" long with pivot rods each end and 2 projections 1 each end and is marked with RB1-2970 N 3. i cannot see any likely position to re-install it. Any ideas please?
When I was disassembling at 5:21 the plastic clip broke. I cleaned up the solenoids and reassembled without the plastic clip. Unfortunately that must have been an important piece as the paper is now jamming immediately. Before it would print one page then jam.
Ich habe probleme mit dem paper jam bei meinem alten HP laserjet 4p. zunächst dachte ich, es liegt am "billigen" papier, daß der drucker immer 2 seiten eingezogen hat - daran lag es nicht. ich habe auch alle sichtbaren gummi-rollen gereinigt, aber das hat auch nicht geholfen. dann habe ich gelesen, daß es an der magnetspule liegt. in der tat war der stift, der den D-ring (papiereinzug) blockiert, immer wieder drin geblieben. also habe ich meinen durcker anhand dieser anleitung auseinander genommen und die spule bzw. das blech gereinigt und wieder zusammengebaut. achtung: beim abziehen des gehäuses sollte man den stecker für die Tasten / display abziehen. dieser sitzt unter der klappe für Speichererweiterung auf der linken seite. außerdem muß man die platine mit LPT/COM komplett abschrauben und abstecken. der zusammenbau ist auch etwas knifflig, da muß man das board wieder so draufstecken, daß die zwei weißen anschlüsse (stecker) dran passen. und noch was: beim zusammenbauen unbedingt drauf achten, daß der dreh-stift (links vom D-ring), richtig rum sitzt. er sorgt dafür, daß der drucker erkennt, ob die papier-schublade drin ist. beim zusammenbauen kann er sich verdrehen und falsch rum stehen, dann muß man den drucker wieder fast ganz auseinander bauen muß (war bei mir leider so). danke, es ist eine super gute anleitung und mein alter drucker funktioniert wieder!
I found where my spare piece goes! All back together and working. Strongly recommend you follow Brent Rasmussen's extra step for both dis-assembly and re-assembly. Thanks.
I hate to throw out my 4L I just put in a brand new toner. This 4l never even pulls the paper at all then goes to error. A nasty sound is heard when paper is attemting to feed. Anybody wabt a shot to repair ?
Many Thanks for an excellent procedure. I would never have been able to disassemble the thing, let alone fix it, without your guidance. Thanks to you my 25 year old HP 4L is back in business and I only had one screw left over.
As I sit here in disbelief...this worked great. It took less than an hour and I wrote down every step of the way so I could easily go back and reassemble. The hardest step was putting the bottom tray back on...the two white connectors and the black ones didn't quite want to go back in. All I needed was a screw driver, a couple q-tips, some goof off and a very small flat-head screwdriver for the plastic clip part. I'll take this laser printer over any of the inkjets out there. Thanks!!!
Thank You for taking the time to do this video. It took me a bit over an hour and 2 beers and my printer is working perfectly! Again, THANK YOU!
Added my two cents, I too hate putting good machines out to pasture before their time. Your video was excellent, cleaned the
solenoids as advise and printer is behaving like new. BTW my envelope print function wasn't working prior to repair - it is now!! Thank you!
Yes, this tutorial does help to fix the printer. I found the second solenoid much later. I'm wondering where the sticky brown cream is coming from. That solenoid does couple the black front-side O-roller to the gear and is responsible for both envelope feed and paper-tray feed. When it sticks for some 1/10 second, the printer stops showing paper jam message.
Brilliant -thanks - this also works for a LaserJet 4MP - it's very similar except to remove the bottom plate part you also need to unscrew the rear piece where flat feeds come out and the mains on/off switch chunk.
That means you then don't need to force apart the metal plate & circuit board from the body - it just lifts out. But keep your concentration up!
I also have 2 screws left over and the paper tray is a struggle to get in .. but it keeps my 21 yr old printer working - ink jets, pah..
Excellent video. It took me 2.5 hours to do it; both solenoids needed cleaning. I used alcohol, Q tips, and a dental pick to clean the solenoids in place. I had a couple of difficulties on reassembly. The paper sensor arm fell out when I turned over the printer during disassembly (it's in loose) and I had to figure out where to put it back, without much help from the low-contrast photos in the HP 4L service manual. When reinstalling the D roller, I thought it might be important to get it back in exactly the position it was on disassembly, where the solenoid arm could be tucked behind it by rocking the D roller slightly. I used Brent Rasmussen's method for getting the main board back in place; that made it much easier.
Thanks for the video and for the explanatory comments below.
Roger
Thank you! I followed your instructions and it was that first solenoid that was sticking badly. Used goo gone to remove the residue and it is now printing like a charm! The printer had been on a shelf for a few years and initially printed well when I put it back in service, but it choked during a longer job (probably heated up just enough to gum up the residue) and it would jam just past the point where the paper was pulled from the tray. Putting it back together was hard, but I got it!
Thanks to your excellent guide I have just resurrected my 1993 Laserjet 4P :-).
My paper jam issue had been gradually getting worse until finally it would not feed at all. I had assumed that it was the rubber rollers that had failed, I would never have thought that the solenoids were sticking. The 4P is very similar to the 4L but I had to remove a few more parts to gain access to the solenoids. I had to remove the fusion roller from the rear and the power switch assembly from the side.
I had 3 screws left over toward the end of reassembly. I then remembered that there were 2 underneath the controller board and one recessed down a deep hole behind the mains switch assembly. Watch out for the small (3cm long) black plastic piece that sits with its axle in 2 notches when removing the lower metal cover and main PCB assembly.
Thanks a million! This is the second time I have fixed this printer, thanks to your video. Brent's suggestion makes it very easy, so make sure to do it. Besides the sticking solenoid, my black roller in the roller assembly was also worn. I put it back together, taking care to place the D roller in the same position as it was when I took it apart, but it still did not work. I had read somewhere else that one can brush some white glue onto the worn roller, and that would help. Took it apart again, put the glue on, and lo and behold, now it's working. Thanks all! I love that printer and hate adding to the waste on the planet. Had it since the 90's....
Thanks a lot! I had the same problem. I recommend to take note of the comments below: remove the rear directional paper assembly (Brent Rasmussen), and in case part RB1-2970 N 3/4 falls out: it fits close to the D-roller, near the edge of the device.
Thanks for instructions, it shows steps very well, missing one or to pictures/steps, but those not crucial! No screws leftover ;) Unfortunaly my problem remains. The other solution is to try to make better grip of black roler either by benzin or maybe with sandpaper. Black roler near D roler is very smooth/sleapery. Btw my problem is the paper got stuck on first draw/page everytime, nothing is printed. This is happening after one time it draw many paper one time, maybe 20pages,and it got stuck.
Great tutorial! The problem started slowly with my printer. It would jam every 5 or 6 pages until eventually it would only printer every other page. Cleaning the solenoid assemblies did the trick! My 20+ year old HP 4L lives on!
Thank U soooo muuch. My printer was in my garaje 4 years and now it´s working perfect cleaning that stick thing. 1994 model, 20 years!! I also sand the foam roller and followed the Brent tip for the white conectors. Gracias desde España!!
Thank you so much for this tutorial. I revived my 27 year old printer.
The fuser should have been taken off the back end (3 screws and pull out) first. Then when you get to 2min47sec those 2 white plugs would not be there. A lot easier and then put the fuser back in last. But this is the best video I have seen for the HP4L to replace the Controller Board.
Thanks for the detailed video. I need to change my Pickup Feed Roller. Presumably the procedure is similar to what you have described, or is there an easier method to just change the D Roller
haven't even tried it yet but i have everyone hope it will work. the video is beaut. clear, calm, not confusing. he makes good videos. good man. thanks a lot. my 4L might live on... :) they don't make 'em like that any more, I think?
Note for minute 4:22: This screw is not necessary to remove. (At least for me.)
Note for minute 4:50: The D roller prevents you from easy access to the screw. However, when you unscrew the metal sheet with the many cogwheels from the side, you can easily rotate the D roller away. I prefer this method. The cogwheels are not indexed, so it's allowed to assemble them in any rotational position.
May I add subtitles to your helpful video?
Thank you! I just fixed mine and printed a bunch of sheets with no jams!!! Thank you again!
Thanks man! You saved me a few meters of my nervous web system.
Also, no leftovers (for the first time ever)
Hey, it worked, printed 160 pages in a row w/o jammin! Thank you cstcst and also thanks to Brant for the golden tip by re-installing the main board!
Great video - I love these printers.. Having looked around my printer a few times I found that I can clean one of the solenoids without disassembling. Take the paper tray out and look for a hole at the front of the printer next to the D roller. You can see a 10 pin socket inside. From this hole you can get a Q tip in to clean the sticky stuff off. Fixed it for me :) #NoDisassemble
Brilliant! Best DIY tutorial I've seen on any subject on the web. Thanks! (BTW I have a screw left over if you need one :)
Thank you, that fixed our 4L jamming! Thank you very much!!!
Worked a treat... my laserjet 4l lives on
I have a printer again! Thank you so much for posting this very excellent video.
Fixed my 4L jamming! Many thanks!!!
To get the main board re-installed correctly: In the back, remove the screws that hold the rear directional paper assembly, and pull the assembly out. The two white connectors will come with it. Install the main board, properly seating the two black connectors, then re-install the rear directional paper assembly, which will connect the two white connectors to the main board properly. If you don't take the rear assembly out, you will almost always screw up the two black connectors on the main board.
Great tutorial., thanks ! No more paper jam on my HP4L !
I am so grateful, finally, it works
Great video very helpful... but I need help, on releasing the main cct board a plastic part fell out from somewhere. It is a molded and is about 2" long with pivot rods each end and 2 projections 1 each end and is marked with RB1-2970 N 3. i cannot see any likely position to re-install it. Any ideas please?
You are the MAN! Thanks !!!!! great guide! I manage to FIX my HP 4L :)))))
When I was disassembling at 5:21 the plastic clip broke. I cleaned up the solenoids and reassembled without the plastic clip. Unfortunately that must have been an important piece as the paper is now jamming immediately. Before it would print one page then jam.
Ich habe probleme mit dem paper jam bei meinem alten HP laserjet 4p. zunächst dachte ich, es liegt am "billigen" papier, daß der drucker immer 2 seiten eingezogen hat - daran lag es nicht. ich habe auch alle sichtbaren gummi-rollen gereinigt, aber das hat auch nicht geholfen. dann habe ich gelesen, daß es an der magnetspule liegt. in der tat war der stift, der den D-ring (papiereinzug) blockiert, immer wieder drin geblieben.
also habe ich meinen durcker anhand dieser anleitung auseinander genommen und die spule bzw. das blech gereinigt und wieder zusammengebaut.
achtung: beim abziehen des gehäuses sollte man den stecker für die Tasten / display abziehen. dieser sitzt unter der klappe für Speichererweiterung auf der linken seite.
außerdem muß man die platine mit LPT/COM komplett abschrauben und abstecken.
der zusammenbau ist auch etwas knifflig, da muß man das board wieder so draufstecken, daß die zwei weißen anschlüsse (stecker) dran passen.
und noch was: beim zusammenbauen unbedingt drauf achten, daß der dreh-stift (links vom D-ring), richtig rum sitzt. er sorgt dafür, daß der drucker erkennt, ob die papier-schublade drin ist. beim zusammenbauen kann er sich verdrehen und falsch rum stehen, dann muß man den drucker wieder fast ganz auseinander bauen muß (war bei mir leider so).
danke, es ist eine super gute anleitung und mein alter drucker funktioniert wieder!
Thanks, great guide. It fixed my printer, for the second time.
Thank you this helped me out a lot!
Thanks, works great!
Hello Worked for me as well many thx
I found where my spare piece goes! All back together and working. Strongly recommend you follow Brent Rasmussen's extra step for both dis-assembly and re-assembly. Thanks.
Ive doen the same and have no idea where it goes back...thoughts? clues? commiserations?
I hate to throw out my 4L I just put in a brand new toner. This 4l never even pulls the paper at all then goes to error. A nasty sound is heard when paper is attemting to feed. Anybody wabt a shot to repair ?