Solved

Printing trouble

Posted on 1998-08-12
10
180 Views
Last Modified: 2010-04-12
I have an apple laserwriter II printer that prints good on the right side of the page but the print gets really light on the left side. I replaced the toner cartrige but the problem is still there. Does anyone know of a reason why this might be happening.
0
Comment
Question by:fisch
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 4
10 Comments
 
LVL 2

Expert Comment

by:ryans
ID: 2014683
Check to see if the "corona" wire is not broken.  To find "hair like" wire, check out your cleaning procedure.  When you open the lid, look straight down. The wire runs parallel to the rollers.  Maybe the wire could also use a good cleaning.  Let me know if this not clear.
0
 
LVL 6

Expert Comment

by:sgenther
ID: 2014684
May also be the fuser...but most likely as ryans said..dirty corona wire..you can use caned air to effectivly clean inside of printer.note: the first few copies will come out dirty but it will then clean its self up.
0
 

Accepted Solution

by:
Aussieglider earned 50 total points
ID: 2014685
There are several things that cause uneven print density in any type of toner printer/photocopier. The machine consists of several stages of image development. The drum is charged to a high voltage while rotating, ususally by a 'corona' wire which runs the length of the drum. This wire is very fine. Most laser printers don't allow you access to this wire. The next stage is exposure. This is where the laser light 'draws' the image on the rotating drum. The drum is classified as a photoconductor and when exposed to light after being charged, the exposed areas will discharge to a lower potential. Then the development unit comes into action. it has a voltage bias on what is called a mag roller, approx equal to the charged level of the drum. The toner particules are statically attracted to this mag roller. The potential difference between the toner on the mag roller and the exposed areas of the drum cause the toner to transfer to the exposed areas of the drum. The drum continues to rotate and the paper is next in the path. The paper passes between the drum and transfer corona. The one you probably can get in to clean. This whole process happens quite quickly and the drum circumference is used more than once for a single print. The paper then goes through the fuser unit. This unit is basically two heated rollers, with a lot of pressure between them that the paper passes through. This ascually melts and forces the toner particules into the surface of the paper.
I can suggest the following diagnosis.
If you have an un-even image after replacing the toner cartridge, the most likely problem is in the dev unit.You will probably find that the dev level is low. A way to find out is to remove the image unit (drum/toner/dev) from that laser printer, hold it firmly while horizontal and slide it left to right to try to even out the level of dev inside it. The other option may be that the drum has been exposed to light. If any drum is exposed to light,(especially sunlight) this will damage the drum. The charge and transfer conrona's can also be cleaned. Be careful though, these wires are usually gold plated and thinner than a human hair. If one of these wires is broken, the printer will just not work and only indicate a error code. The last this is the fuser. It is unlikley that this is the problem as the fuser does'nt give this type of image problem that you have. One final possibility is wether it is a LED or laser printer, Clean the LED assembly with a lint free cloth and some isopropyl alcholol or sometimes the polygon mirror within the laser assembly can attract dust (although supposed to be sealed) on the leading edge of the rotational direction. This would cause not enough light being reflected to the drum, giving lighter copies at one edge of the paper. If you can borrow another image unit to test it, this could help prove whether this is the actual problem.
WARNING - There are extremely high voltages used in laser printers. UP TO 8000 VOLTS. Be very careful when working within and it is always best to remove power completley.

I hope the above information helps you. There are many different things that can affect image quality, and if you can understand the basic operation of the machine, you should be well on the way to diagnosing and fixing your problem.
END

0
Space-Age Communications Transitions to DevOps

ViaSat, a global provider of satellite and wireless communications, securely connects businesses, governments, and organizations to the Internet. Learn how ViaSat’s Network Solutions Engineer, drove the transition from a traditional network support to a DevOps-centric model.

 
LVL 6

Expert Comment

by:sgenther
ID: 2014686
Hey Aussie....are you familiar with this printer?..The Develper unit is part of the toner cartridge in these..in fact they look just like a HP II/III inside. Other comment: did you just read that answer out of a text book or what?
0
 
LVL 2

Expert Comment

by:ryans
ID: 2014687
So what WAS the answer??  
0
 
LVL 6

Expert Comment

by:sgenther
ID: 2014688
Laff...ryans...my point exactly.
0
 
LVL 2

Expert Comment

by:ryans
ID: 2014689
sgenther,
I guess we may have to use the old "cut & paste" feature, or better yet; compile all the suggestions into one answer.  Hey, for the WIN95 section here on EE, I'll the post my RESOURCE KIT BOOK and the answer for every question. :)
0
 
LVL 6

Expert Comment

by:sgenther
ID: 2014690
Ryans...and remember...WARNING - There are extremely high voltages used in laser printers. UP TO 8000 VOLTS. Be very careful when working within and it is always best to remove power completley.
:)
0
 
LVL 2

Expert Comment

by:ryans
ID: 2014691
sgenther,
About the only thing not mentioned:

Also, make sure you don't have the "new technology" printers that uses "nuclear fision" to fuse the toner to the paper.  It may cause health problems! :)
0
 
LVL 6

Expert Comment

by:sgenther
ID: 2014692
Roflmao.....and make sure your ozone filter is in...or you may get a hole in your head.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Causes of paper jams:The following are the main causes of paper jams. Guides:If the guides for the paper are not set correctly they may cause the paper to enter at an angle. You should ensure that the guides are set correctly for the paper type a…
Printers have changed substantially in the last 30 or so years, not just in technical capabilities but in cost and usage as well.  Printers were originally used for interfacing with the operator, not necessarily for printing copy or pictures. In …
In an interesting question (https://www.experts-exchange.com/questions/29008360/) here at Experts Exchange, a member asked how to split a single image into multiple images. The primary usage for this is to place many photographs on a flatbed scanner…
This video Micro Tutorial shows how to password-protect PDF files with free software. Many software products can do this, such as Adobe Acrobat (but not Adobe Reader), Nuance PaperPort, and Nuance Power PDF, but they are not free products. This vide…

724 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question