asked Jan 3, 2006 at 7:14am
Hp HP LaserJet 4

HP Laserjet 4 printing blank pages

My HPLJ4 keeps printing blank pages, even during a self-test. Tried a new fuser, laser/scanner, dc controller, toner cartridges. Nothing works. The cartridge doors are being opened when inserted. Anyone got any brilliant ideas?
Sound like a computer and communications issue. First thing is to turn off the printer, disconnect the cable which goes from the computer to the printer and turn the printer back on. If it is a LJ 4 since your title is confusing, just go thru the menu to test menu and print a test page. If it prints ok, then the issue is the computer and/or driver. Now before reconnecting the printer to the computer, remove the printer from the operating system on the computer, turn off the computer, reconnect the printer, turn on the computer and reinstall and see if it now works.
by dmzcompute on Nov 26, 2006 at 4:35pm Add comment
It's been covered on the forum before, but there are 3 things that can cause blank pages. The most common is the laser shutter pops off on the spring side and blocks the laser from hitting the cartridge. The shutter opens when the cartridge is inserted. The cartridge guide that sits above and behind the cartridge misteriously gets eaten by the printer. Without it, the cartridge rides too high for the toner to transfer. The high voltage power supply goes totally dead. If the first 2 are ok, then replace the high voltage power supply. While the laser scanner can cause the problem, you would get an error code. With the 3 causes I gave, you won't.
by moe on Jan 3, 2006 at 9:56am Add comment
Thank you for your most timely reply. If it is the High Voltage Power supply, if it is dead, wouldn't the printer be without power?

I also installed a new transfer roller without success and the printer cartridge looks to be funtioning fine. I'm hoping it's the power supply. Thanks for your help. I will keep y'all posted on progress. - Anonymous
It was the spring attached to the laser/scanner shutter. It was off and the black plastic arm that moves the shutter out of the way when a toner cart is inserted was also out of position. Fixed up both and printing returned to normal. Thanks for all your help. - Anonymous
Agree with Moe and a couple of other things. First your post sounds familar like from last week or so in which I told the user to do a half test and check the drum of the toner cartridge for any image. If there is an image on the toner cartridge, then you issue may be the transfer roller or its contacts. The other item is to remove the formatter and try a engine test with the button on the inside right of the manual feed area. If the page prints lines ok, then your issue is the formatter.
by dmzcompute on Jan 3, 2006 at 10:07am Add comment
Always the confusion. There are 2 power supplies in the printer. One the low voltage power supply supplies voltage to all the boards, fans, etc. The high voltage ps only supplies voltage to the toner cartridge.
by dmzcompute on Jan 3, 2006 at 11:29am Add comment
If you pull out the paper tray and flip the printer over, you're looking at the high voltage power supply. If I remember right, 2 screws and a couple of snaps holding it in place. You really should rule out the first 2 options I cited before you replace it. Always go for the low or no cost fixes first.
by moe on Jan 3, 2006 at 1:42pm Add comment
You need to recheck your first post. In it you said you changed the laser/scanner. If you did you would have seen the shutter being off. Lucky for you Moe missed that in your original post.
by dmzcompute on Jan 4, 2006 at 2:24pm Add comment
I didn't miss it. I saw that he'd replaced the scanner and I did tell him to rule out the shutter and the cartridge guide before he replaced the HV power supply. I kind of suspected the shutter spring from the beginning. That's what it always turns out to be when people mess with the scanner assy. or anything near it.
by moe on Jan 4, 2006 at 10:14pm Add comment
I have the same problem..where would I look to find the laser/scanner shutter?
by unknown on Jan 27, 2006 at 12:19pm Add comment
Under the top cover and below and by the front of the laser/scanner assembly (black box). Control of the shutter is on the left side of the laser/scanner.
by dmzcompute on Jan 27, 2006 at 12:30pm Add comment
Thanks Moe, and everyone else, for your advice on this board -- I have a used Laserjet 4+ I bought from E-bay that printed only blank pages and after reading your solution, found the laser shutter misaligned and was able to fix it and now have a GREAT printer! Thanks again!
by jase115 on Sep 24, 2006 at 8:00pm Add comment
It keeps printing blank pages. Even if after I reboot the machine, it keeps on doing it and rendered the printer useless. I have downloaded and installed the driver from HP site but to no avail. I checked the setting for any printer que and found nothing there. I am completely helpless.
by bentsao on Nov 26, 2006 at 4:27pm Add comment
How did you fix the shutter?
by Anonymous on Apr 30, 2008 at 6:40pm Add comment
I mean the black plastic arm... Do I have to take the printer apart?
by Anonymous on Apr 30, 2008 at 6:44pm Add comment
yeah, sure. Take it all apart in little itty bitty pieces.
by Anonymous on Apr 30, 2008 at 8:16pm Add comment
Same problem - white pages. The printer has worked fine for 15 years at least, so I am not too upset that it stopped working. I had a funny smell in the room when I turned it on today, and the there seems to be a humming noise that was not there before. When I print, either via computer or self-test, the pages are completely white.
I don't understand the instructions that are given here. Can someone please be more specific about what I should look at? What spring? What shutter?
by unknown on Aug 9, 2009 at 12:43pm Add comment
I think it's covered in enough detail if you do read the posts. If the printer just quit working and you didn't touch it since the last time it was working, then the funny smell might be the high voltage power supply burning up. Of course, people always seem to omit important things in their posts like error codes on the display panel. Contrary to public opinion, printer techs are NOT psychic. If you hold back information, it becomes a lot harder to help.
by moe on Aug 9, 2009 at 12:51pm Add comment
The printer has been working fine and I did not touch it. No error codes. I will go out and buy a new printer. It definitely feels like an electrical problem, not mechanical. I just find it odd that the electronic thinks everything is ok. How can I make sure it is the high voltage supply?
by unknown on Aug 9, 2009 at 12:54pm Add comment
From a pure troubleshooting viewpoint: If you did not touch the printer and that includes opening it and removing the toner cartridge, then the ONLY failure that would cause blank pages without an accompanying error code is the HV power supply. So, I am going strictly by your input here. There is a test you can do to see if there's any image formation on the cartridge. Put a sheet in the MF tray and when you see the tail end go into the printer after you send a test page, quickly open the lid and remove the toner cartridge. Pull back the shutter and look at the drum. If you see an image composed of toner powder, then there is HV present, if not then it's probably the HV power supply. They are very easy to replace and not expensive. If you want to give it a go, I have lots in stock. Click on my name to email me for pricing and ordering info.
by moe on Aug 9, 2009 at 1:09pm Add comment
You are corrent, "not touching it" means I did not tamper with the toner cartridge - I just turned it on.
I will email you about the transformer. - Anonymous
The above should read "correct" and "power supply" (instead of transformer).
by unknown on Aug 9, 2009 at 1:18pm Add comment
I have the same problem. I have a Laserjet 4 Plus and upon powering up, it just constantly spits out blank pages (in 'Online' mode).

1 - Printing test pages from the test menu in 'Offline' mode WORKS. This tells me the printer can actually print just fine and the issue is a mechanical problem.

2 - I checked the black plastic cartridge guard above the yellow high temperature-warning label, it isn't terribly loose or falling off. It does have some play though... the whole plastic part I can shake a little bit, and the plastic flap has flex to it. It all feels normal though. Should the unit be super tight and not be shakeable?

3 - I took the printer top off and inspected the black plastic shutter switch on the left side of the laser unit. It seems to be very much in the correct position, and when I slide the cartridge in, the switch activates. There is some play in the switch, in all positions. Does that matter? I tried holding the switch tightly to one side while in Online mode to see if it would stop the blank pages coming out. Nothing happened.

4 - FYI the toner cartridge we got 2 months ago. Worked great initially, until this blank pages problem came about. Again, test pages print just fine. Could the blank page problem be related to this 'new' cartridge (which is obviously refurbished, this day in age)?
by Cablestein on Aug 18, 2009 at 11:40am Add comment
If you can print & read self test sheets generated from the printer's operators panel, then you DON'T have a mechanical problem! Think about it. The source from where the data comes from is probably your issue for blank pages. Disconnect the data (source) cable you have attached to the printer. Do you still get constant blank pages on printer power up, when it's online?
Good luck!
by Anonymous on Aug 18, 2009 at 1:43pm Add comment
Your troubleshooting theory needs a lot of work. First of all the printer is printing. All the things you cited will cause blank pages no matter what. This also totally eliminates a mechanical problem since the printer is printing in test mode. Turn it off and disconnect the cable to the computer. Now power it up and see if it cranks out blank pages. If it does, you have a formatter issue. If it doesn't, you have a problem with the computer, drivers, cable etc.
by moe on Aug 18, 2009 at 1:55pm Add comment
Hello all

I know this is an old thread, please help me if anyone has a little free time.

I have the exact problem. A LaserJet4 that used to work and print fine, until it was replaced a few years ago by a newer and better(?) Lexmark.

Recently, when the Lexmark had to be serviced I thought maybe I can use the LaserJet4 in the meantime. Since it was sitting in the garage for so long, I decided to take it apart to give it a good dusting.

In the order mentioned I removed the back cover, the hot roller assembly in the back (is this called the fuser?), the top cover, the right side cover, the network card and of course the cartridge. Pretty much I could see through from front to back (and vice versa) and gave it a good blow with compressed air.

Put everything back together, printer started fine, LCD said "warming up" and it did, I then checked the menus, configuration, network settings, everything was exactly as it was a few years ago(!), loaded some paper, tried a "PCL Demo Page" test, got a blank page, tried to print from my windows PC (still had the driver installed), everything "working" except ink on the paper. I mean nothing not the slightest smear of ink. The printer's back side does feel warm to the touch (actually on the hot side) and the paper comes out slightly warm, so I am assuming the High Voltage PS is working.

I must have defintely messed up something doing this overhaul (!?) problem is, I can't think of anything since I was very careful during the removal/re-assembling and repeated troubleshooting checks have not been productive at all.

This is a 1993 made HP printer that gave me many years of good service so I will not feel devastated by its loss. But it's "eating me up" what did I do wrong so I know -just in case- for the future ...

Printer works except for ink on the paper, what could the cause be?

Thanks in advance for your time.

Dim Pan
by unknown on Sep 17, 2010 at 12:45pm Add comment
You either dislodged the metal shutter at the front of the laser scanner, or blew off the cartridge guide. The guide is a black plastic part that clips on above the toner cartridge. But, I repeat myself because I already gave this advice at the beginning of the thread.
by moe on Sep 17, 2010 at 1:47pm Add comment
Anonymous said that his problem with the printer was the spring attached to the laser/scanner shutter and that the the black plastic arm that moves the shutter out of the way when a toner cart is inserted was also out of position. He said he fixed them. I think I may have the same problem. Can anyone tell me how do you fix those? I neever opened up my printer before so I kinda need a step by step guide to doing it. Thank you very much.

My issue is:

1. Printer prints blanks
2. Printer DOES NOT print test pages
3. The Cartridge is not the issue

by HP 4 Plus on Dec 18, 2010 at 6:20am Add comment
Remove right side cover. Open front lid, latch at front, push tab at back. 1 screw under lid, 2 screws at the back. Put a small flat blade screwdriver in 2 slots at front and pull towards you to release latches, while pulling up at the front. Top cover will come off and there is a connector on right that you pull off. You now have access to the scanner.
by moe on Dec 18, 2010 at 8:49am Add comment
My HP Laserjet 4+ only prints on 1/4th of the page. Test page prints fine. Any suggestions? I tried a cold reset and still the same printing problem. Also swapped it with another one I have and the other printer does the same thing.
by unknown on Feb 26, 2011 at 9:10am Add comment
Lets use some common sense here. If it happens with another printer, the problem is the driver or settings within the driver or application that is the problem and not the printer. Remove the printer driver and reload and see what happens.
by dmzcompute on Feb 26, 2011 at 11:36am Add comment
Similar issue with HP5N.

Initial pages are blank then the image slowly gets darker and at about 5-6 pages comes dark.

Tried 3 new cartridges ( one genuine HP 2 x generic)and the printer was cleaned and serviced.

Is there any way to test the HV power supply?

Regards, KH
by Lumpy20 on May 7, 2013 at 5:50pm Add comment
I am having similar issues. I have a HP Color LaserJetPro CP1525NW.
I don't even recall why at this point, but I have opened the rack to get at the toner cartridges (i assume to check them because i hadn't used it in a few months and it had been sitting.)
It printed prior to open the rack that holds the cartridges, but following this, and replacement, it now prints blank pages.
It appears that there is cartridge on the drums when I open them back up, but I need to check mid-feed like the prior posts state.

I am wondering since the rack with cartridges caught and I forced it a little if i knocked something out of alignment, etc., when opening up.

Can I get a few pointers before opening this thing up to look and see if the spring you guys keep referring to is also my issue.

will print tests from browser utility, from printer panel itself, etc, it just prints blank pages.

Thanks for any guidance.

P.S. I am a electronics junkie, just didn't finish the second year of electronics tech program!
by scott.kaul on Dec 3, 2013 at 3:43am Add comment
This is a thread for an old skool black and white printer. You would be better served starting your own thread. I don't know how much good it will do you as it's pretty near impossible to help someone with no printer service experience who's broken their printer while trying to fix it. The printer would have to be in front of us so we can see what happened. Good luck. - moe
I have read all the posts below, and it seems this is also my problem. I just need to know where to find the scanner/printer shutter spring/mech? Please advise if you can.. Thanks
by CindyLooWho on Feb 27, 2014 at 6:47am Add comment
You have to remove the top. You'll see a black box, that's the laser assy. The shutter is in the front of it.
by moe on Feb 27, 2014 at 11:39am Add comment
Thank you so much, is it difficult to remove the top? - CindyLooWho
A little test that might help; if you turn the printer upside down (only works with small printers) and your prints are actually coming out right, it sureluy IS the shutter...
by unknown on Nov 10, 2014 at 9:43am Add comment
dear cwpauline,
i had the same problem in my brother laser printer mfc-7840w
after taking half of the printer apart, i have found the problem...
It was the little white plastic tooth that is pushed by a spring ... It's located on the left side inside the printer, it's purpose is to open the laser shutter ( it's a black roller like stick that is located inside the laser box and it's black tooth is suppose to be pushed by the white tooth when the laser box is installed inside the printer... Looks like during the delivery, the white tooth was misplaced which caused the black roller to roll down and therefore covering the laser beam) ...
There is no electronic connection between the tooth and the motherboard... Therefore the printer didn't display any errors when the blank page print happened ..
after taking the laser box out, and placing the white tooth with the spring in its original position, the problem was solved...
The printer works great now...
by arrowvitaly on Dec 13, 2014 at 11:55am Add comment
i install the software, buy new cartridges but prints test pages and any documents in blank can you support me what is the case?
by unknown on Jan 23, 2015 at 4:37am Add comment
Did you pull the seal out of the toner cartridge?
by moe on Jan 23, 2015 at 11:34am Add comment