HP4M printer suddenly has crummy output

[Muse]

I've had this since it was practically new. The guy who sold it to me said he'd only made 10 prints on it or so, and it looked and acted just like that. Never had a serious problem with the printer until now.

When I bought it, it was an HP4, which happened to already have 6 MB of memory, so by adding the Postscript card, it became essentially an HP4M. I got it in 1994 or so, and right away purchased the postscript card for it.

I've replaced the laser cartridge around 1/2 a dozen times, always with brand new cartridges, never recycled cartridges.

My current cartridge has been in the machine a long time (I haven't been printing a lot), maybe 3-4 years, I'd guess, maybe more (5?).

Suddenly, about 2-3 weeks ago the prints often (not always!) come out looking weird. Where it's supposed to be white, it's kind of gray in a lot of places (almost the whole sheet, but it's variable -- It's sort of banded vertically). I thought to myself that if I remove the cartridge and shake it to jostle loose the toner, it might start acting OK (I could hope... ), but that didn't help. I noticed some toner on the outside of the cartridge, including the ivory colored tube (around 10" long?). I couldn't turn that, but I wiped it off, and cleaned the cartridge with a cloth and soft brush and compressed air, but the prints are still smudgy.

I've many times done duplexing with the printer, although I know it's not officially supported. I do this by printing on the back side, using manual feed. I haven't done that for a while, though, and very little at all in recent times. Certainly, the problem has come on long since I've done any duplexing.

What could be wrong? Can I fix this myself? Is the printer worth fixing?

 

[PottedMeat]

I dunno if it's worth fixing but try looking here:

HP LaserJet 4/4M/4+ Combined Service Manual - PDF

Look around page 7-36.

I've got a LJ4 still goin' strong I picked up at Goodwill with 250K+ pages on it. Good luck.

 

[OdiN]

Have you ever done maintenance to it? It probably could use a new transfer roller, and it may need a new fuser assembly.

I'd say check the transfer roller first.

Also...the HP4s I believe had to have the laser unit replaced from time to time.

 

[Muse]

Originally posted by: OdiN
Have you ever done maintenance to it? It probably could use a new transfer roller, and it may need a new fuser assembly.

I'd say check the transfer roller first.

Also...the HP4s I believe had to have the laser unit replaced from time to time.

I've never done anything that could (I think) be called "maintenance." Maybe I should, or should have. I was unaware of anything I had to or could do. The only things I've done is clear paper jams, basically, and replace empty cartridges. I suppose this could just be a leaking cartridge, but figure I should get some input. I'll read that service manual as indicated, thanks PottedMeat.

I wonder about the fuser assembly. As HP LJ 4/4M's go, this has gotten very light use. They were/are workhorse office server printers with (compared to mine) huge duty cycles. It's hard for me to imagine that it needs a laser replacement at this point. The print is still razor sharp, just like it's always been. That's a major reason I bought it (it was quite expensive), and also the fact that I figured it would be relatively trouble free (which it has been up until now).

I will have to look into the transfer roller and fuser assembly concept. I'd like to have some idea what precisely is wrong that's causing the dirty prints, though. Thanks for the help.

 

[Muse]

Originally posted by: PottedMeat
I dunno if it's worth fixing but try looking here:

HP LaserJet 4/4M/4+ Combined Service Manual - PDF

Look around page 7-36.

I've got a LJ4 still goin' strong I picked up at Goodwill with 250K+ pages on it. Good luck.

PottedMeat, I'm hitting that page, but the PDF isn't loading. The page is blank, at least here on my laptop.

Mmm, a few minutes later I discovered an Acrobat Accept/Decline screen for version 8.0. It's loading now.

When you say pages 7-36 do you mean according to Adobe Acrobat or the table of contents of the manual? TIA.

 

[OdiN]

Originally posted by: Muse

Originally posted by: OdiN
Have you ever done maintenance to it? It probably could use a new transfer roller, and it may need a new fuser assembly.

I'd say check the transfer roller first.

Also...the HP4s I believe had to have the laser unit replaced from time to time.

I've never done anything that could (I think) be called "maintenance." Maybe I should, or should have. I was unaware of anything I had to or could do. The only things I've done is clear paper jams, basically, and replace empty cartridges. I suppose this could just be a leaking cartridge, but figure I should get some input. I'll read that service manual as indicated, thanks PottedMeat.

I wonder about the fuser assembly. As HP LJ 4/4M's go, this has gotten very light use. They were/are workhorse office server printers with (compared to mine) huge duty cycles. It's hard for me to imagine that it needs a laser replacement at this point. The print is still razor sharp, just like it's always been. That's a major reason I bought it (it was quite expensive), and also the fact that I figured it would be relatively trouble free (which it has been up until now).

I will have to look into the transfer roller and fuser assembly concept. I'd like to have some idea what precisely is wrong that's causing the dirty prints, though. Thanks for the help.

You need to pull a current page count to determine how many pages have gone through your fuser, and then find your duty cycle of the fuser. I don't remember what it is on an LJ4. I know the 8150's I use are 350,000 pages.

Transfer rollers just get used, dirty, etc. and need to be replaced. They are not that expensive and I would look there first, especially if you think your page count on this particular fuser is low.

I doubt that it is a leaking cartridge. How old is the cartridge? Do you have a lot of paper bits hanging around in the printer? This bad quality can be caused by the toner cartridge picking up bits of paper dust and the toner mixing with the dust. If you have an extra cartridge you can put it in and print a test page to see what happens. I would think this might be a possibility since the cartridge has been in so long.

But if you've had it since 94 and haven't ever replaced the fuser, that could very well be part of it. They do get old and don't last forever. Yes LJ4's are workhorses and there are lots still around - but they are around because they have been maintained properly.

Also, are you using remanufactured/off brand cartridges or genuine HP cartridges?

 

[Muse]

Originally posted by: OdiN

Originally posted by: Muse

Originally posted by: OdiN
Have you ever done maintenance to it? It probably could use a new transfer roller, and it may need a new fuser assembly.

I'd say check the transfer roller first.

Also...the HP4s I believe had to have the laser unit replaced from time to time.

I've never done anything that could (I think) be called "maintenance." Maybe I should, or should have. I was unaware of anything I had to or could do. The only things I've done is clear paper jams, basically, and replace empty cartridges. I suppose this could just be a leaking cartridge, but figure I should get some input. I'll read that service manual as indicated, thanks PottedMeat.

I wonder about the fuser assembly. As HP LJ 4/4M's go, this has gotten very light use. They were/are workhorse office server printers with (compared to mine) huge duty cycles. It's hard for me to imagine that it needs a laser replacement at this point. The print is still razor sharp, just like it's always been. That's a major reason I bought it (it was quite expensive), and also the fact that I figured it would be relatively trouble free (which it has been up until now).

I will have to look into the transfer roller and fuser assembly concept. I'd like to have some idea what precisely is wrong that's causing the dirty prints, though. Thanks for the help.

You need to pull a current page count to determine how many pages have gone through your fuser, and then find your duty cycle of the fuser. I don't remember what it is on an LJ4. I know the 8150's I use are 350,000 pages.

Transfer rollers just get used, dirty, etc. and need to be replaced. They are not that expensive and I would look there first, especially if you think your page count on this particular fuser is low.

I doubt that it is a leaking cartridge. How old is the cartridge? Do you have a lot of paper bits hanging around in the printer? This bad quality can be caused by the toner cartridge picking up bits of paper dust and the toner mixing with the dust. If you have an extra cartridge you can put it in and print a test page to see what happens. I would think this might be a possibility since the cartridge has been in so long.

But if you've had it since 94 and haven't ever replaced the fuser, that could very well be part of it. They do get old and don't last forever. Yes LJ4's are workhorses and there are lots still around - but they are around because they have been maintained properly.

Also, are you using remanufactured/off brand cartridges or genuine HP cartridges?

I just did the Self Test and it reports 17,350 pages. I figure that qualifies as very low use.

The cartridges I use (every single one since the printer was new, 1993) are genuine HP cartridges and not remanufactured. However, the current cartridge is rather old, since I haven't been using the printer much and my jobs in recent years have been low page count. I'm guessing that I installed this cartridge in 2002-3.

I kind of doubt there's a lot of paper bits in the printer. I do have an extra cartridge, brand new in unopened box. It's been sitting on a shelf since before I inserted the current cartridge (I bought more than one, probably two at the time because it was a good deal and I was also probably concerned about availability). I've since heard that it might be a mistake to assume that it would have an indefinite shelf life. However, I could try it. I'm thinking that if the current cartridge is leaking I should try to clean out the leaked toner before inserting another cartridge. I don't know how I'd go about doing that. I suppose common sense might suggest opening it up as much as possible and vacuuming, both sucking and blowing (I have a vacuum that will blow, too). Also, maybe, dust lightly with a soft brush. There's no big hurry on this. I'm not currently doing anything critical, not printing out my resume or anything like that. However, the prints are getting pretty nasty looking at times, and I know it's time to tackle the problem. Thanks for the help.

 

[OdiN]

You can vacuum it, no need to blow.

But leaking toner will not cause what you are describing. More likely it would be clumped and have dark black toner spots here and there. It sounds like by saying grey that it is more of a uniform spread.

 

[Muse]

Originally posted by: OdiN
You can vacuum it, no need to blow.

But leaking toner will not cause what you are describing. More likely it would be clumped and have dark black toner spots here and there. It sounds like by saying grey that it is more of a uniform spread.

Yes, it doesn't clump at all, no spots whatsoever. It is fairly uniform, but tends to band vertically. It's by no means consistent. The Self Test one-sheet (letter sized) out put yesterday was only faintly gray, so faint that I had to look for grayness. However, the tiny character stuff at the bottom (bottom 1/4 or so) was kind of nasty. Not altogether clear, somewhat grayed, mottled (i.e. not uniform, still, not spotted or clumpy).

Looking at the manual I see they suggest (after other possibilities) trying a different cartridge or changing the transfer roller, such as you suggest. They appear to indicate that this is doable by the user, so I may shop for one online. I haven't been after it 'cause I'm busy, but will probably within a few days.

 

[coolied]

you need a new transfer roller and fuser........... with it being that old, wouldn't be a bad idea to order a maintainance kit from HP (there's a core charge on it, just like car parts, so be sure to ship the stuff you replaced back).............. after 14 years, those parts are going to have to be changed, irregardless of pagecount.

 

[Muse]

Originally posted by: coolied
you need a new transfer roller and fuser........... with it being that old, wouldn't be a bad idea to order a maintainance kit from HP (there's a core charge on it, just like car parts, so be sure to ship the stuff you replaced back).............. after 14 years, those parts are going to have to be changed, irregardless of pagecount.

Online, I'm seeing a lot of refurb kits. Are they chancey? Or should I only think in terms of buying new?

 

[Muse]

I'm considering this kit:

HP4/4M Deluxe maintenance kit (without fuser), $40 shipped. They have an "ultimate" maintenance kit for around $10 more that includes a few more parts but their description makes it sound like this is best for very high usage printers, which mine is not. These kits include a how-to video! The "deluxe" one includes:
- - - -
The kit includes the following new stock parts:

*
Upper exit delivery roller
*
Lower exit delivery roller
*
MP Tray pickup roller and separation pad
*
Main tray pickup roller
*
Delivery assembly belt
*
Transfer roller
*
CD video playable on your PC
*
Service guide
- - - -
If it turns out I need to replace the fuser, they sell refurbished fusers. Their description of the refurb fuser sounds pretty good. Most sellers say just about nothing. Their fuser:

HP4/4M fuser refurb at laserprinterkits.com

 

[Muse]

bump

Anyone comment on my last post? Thanks.

 

[redbeard1]

Originally posted by: coolied
you need a new transfer roller and fuser........... with it being that old, wouldn't be a bad idea to order a maintainance kit from HP (there's a core charge on it, just like car parts, so be sure to ship the stuff you replaced back).............. after 14 years, those parts are going to have to be changed, irregardless of pagecount.

Agreed that this is what you need, a maintenance kit with a fuser.

 

[Muse]

Originally posted by: redbeard1

Originally posted by: coolied
you need a new transfer roller and fuser........... with it being that old, wouldn't be a bad idea to order a maintainance kit from HP (there's a core charge on it, just like car parts, so be sure to ship the stuff you replaced back).............. after 14 years, those parts are going to have to be changed, irregardless of pagecount.

Agreed that this is what you need, a maintenance kit with a fuser.

Hmm. I posted at comp.periphs.printers and two people said they don't think the fuser is a problem:

Maintenance for HP Laserjet 4

In particular, this message:

- - - -
Dan almost certainly not the fuser.
Cartridge possibly or transfer roller, there really isn't much else it can be.
The laser scanner won't cause gray background.
A 4 year old cartridge is likely to have problems, mainly due to wiper blade
aging, this causes gray backgrounds although usually in vertical stripes.
Tony
MS MVP Printing/Imaging

 

[Muse]

Well, I just replaced the cartridge with the genuine HP "new" 5+ year old cartridge and printed a test page and it looks perfect. I guess the transfer roller and fuser assembly are OK.

My new cartridge weighs 3 lb. 1 oz, the one I replaced 2 lb. 12 oz. Is it possible to find out what an empty cartridge would weigh? I'm curious, so I can guage how full my current cartridges are.