Canon MF237w making light copies, how can i fix it

Try this . Make some copies ( at least 5) and open one of the covers while machine is making copies. Remove the paper jam and verify if the copy is blurred. Do this to be sure of what unit is causing the blurred copies. If copy information is good before the paper enter in the fixing unit . That mean the problem is is the fixing unit

Check OPC drum and charging roller.
Go to service mode and set develop
asterisk * button then press at a time 2 and 8 again press asterisk * button
select copier>adjust>develop
touch on develop increase the develop value 10, 20 as your satisfaction..

How many copies did machine make? Could be a drum unit,transfer roller or fixing film in fixing unit

open the scan and make sure that marked ruler like thing where the scana light rest is tightly fixed. that's it ,the error won't appear anymore

http://www.usa.canon.com/cusa/support/consumer/printers_multifunction/pixma_mp_series/pixma_mp830#BrochuresAndManuals

I would download the manual for windows 7 and see if the 'alarm and copy light flash' error is listed. I could not find it referred to in the support area of the canonusa.com website. Also, you could call 1-800-OK CANON and talk to a rep. about this problem.

Good luck on this repair.

try to setting it to default, may can fix the problem

hi canon ir8670 error code E-065 pls help me

* Disable toner save by change in printer driver.
<http://copynews.net/how-to-fix-print-quality-problem-canon-ir-1600-printer.html>

Just fyi, a Canon PC-6e is a copier that is about ten + years old of a model... The drum unit will make the copies better.... But, you most likely need to clean the optic's. Have you tried to make the copies lighter??? If I am correct, there is a small botton on the control pannel that will turn... It will make the copies light one way and darker the other way... Good Luck

adding toner to Canon copiers will not fix copy Quality problems. Do the copies look better if you manually adjust your exposure setting? If so you can clean the optics, which are the mirrors under the glass. Be very careful there are alot of sharp metal edges, that can cut you very easily.
You can use windex.