HP laser printer produces ghost image

This is a HP laserjet 3020. When I print dark images, a ghost image
appears 3" down the page. I replaced the toner cartridge to no avail.
This is not a highly used printer, probably less than 1000 pages
printed in its life. I read somewhere that it could be the optical drum
or fuser but I am not sure how to get to these parts, whether I should
remove the back panels or if I should try to get to it from behind the
toner cartridge. The location does not seem to be obvious. Any
suggestions would be appreciated.

asarangan@yahoo.com wrote:
>This is a HP laserjet 3020. When I print dark images, a ghost image
>appears 3" down the page. I replaced the toner cartridge to no avail.
>This is not a highly used printer, probably less than 1000 pages
>printed in its life. I read somewhere that it could be the optical drum
>or fuser but I am not sure how to get to these parts, whether I should
>remove the back panels or if I should try to get to it from behind the
>toner cartridge. The location does not seem to be obvious. Any
>suggestions would be appreciated.

Firstly ghosting is nearly always a toner cartridge failure in HP monochrome
lasers, specifically it is a combination of the drum and the wiper blade in the
cartridge.
Secondly, the drum diameter in the cartridge used in this printer is exactly 3
inches which indicates that the problem is indeed in the toner cartridge.
The "optical drum" is the same part as the toner cartridge drum.
I am surprised that replacing the cartridge did not fix the problem, did you
use a new or "known to be good" cartridge?
Were the symptoms with the two cartridges exactly identical using the same
source image, in other words could you have two bad cartridges (ghosting is a
fairly common toner cartridge failure)? Can you try the cartridge in another
printer?
The distance of 3 inches between original and ghost does not correspond with
the diameter of either of the fuser rollers. The fuser is hard to remove from
this printer but in any event I do not think it is to blame.
Tony