You can download a .pdf file of the User Manual for this printer for
free from the internet. It is a nice 102 page document with all sorts
of valuable information. Just type in:
Samsung ML-4500 Instruction Manual
and you can find a number of ways to get it for free.
Here is one link to follow:
http://www.nodevice.com/user_manual/samsung/printers/ml-4500.html
Under light or faded prints the following is in the manual:
If a vertical white streak or faded area appears on the page:
• The toner supply is low. You may be able to temporarily
extend the toner cartridge life. See “Redistributing the
Toner” on page 6.2. If this does not improve the print
quality, install a new toner cartridge.
• The paper may not meet paper specifications (for example,
the paper is too moist or too rough). See “Paper
Specifications” on page A.2.
• If the whole page is light, the print resolution setting is too
light or Toner Save Mode may be on. Adjust the print
resolution and Toner Save Mode within the printer
properties. See page 5.7 and 5.8 respectively.
• A combination of faded and smeared defects may indicate
that the toner cartridge needs cleaning. See “Cleaning the
Printer” on page 6.4.
• The surface of LSU part inside the printer may be dirty.
Clean the LSU. See “Cleaning the Printer”.
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Also, the software driver from Samsung offers a lot of settings for
different resolutions (sometimes a lower res will print darker)
and options such as: paper type, envelopes, stickers, etc, and with some
experimentation you will probably find one setting will print darker.
As the trouble shooting area suggests, try different paper, try
redistributing the toner in the cartridge, by removing the cartridge and
rocking it gently back and forth, change other printer properties, etc.
Art
If you are interested in issues surrounding e-waste,
I invite you to enter the discussion at my blog:
http://e-trashtalk.spaces.live.com/