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asked Feb 6, 2004 at 9:10am
Hp HP LaserJet 5SI

LJ 5si ghosting mystery

I’m having a problem with a Laserjet 5si printer. Ghosting that is coming from the fuser hot roller (according to manual). Fuser assembly has been replaced. Three different types of paper have been tried including an HP recommended paper. High voltage power supply board was replaced (not the whole module). Many toner cartridges have been swapped into and out of it. Transfer roller has been swapped in and out. If anyone can help me out on this problem I would greatly appreciate it.
Ghosting refers to an object or letter that is repeated several times down the length of a page at even intervals. The repeated image appears as a light or dark area relative to the surrounding image. This condition most often occurs when a fine gray scale follows a large black pattern. The condition is caused by residual electrical charges left on the surface of the electro-photographic (EP) drum or a lack of toner in the developed region. Ghosting is a condition experienced in one form or another by all devices that use the EP process. Both the developer and the EP drum can produce dark or light ghosting.

NOTE: For a repeating image to be considered ghosting, the image repeating down the page must not be a result of ink from a preprinted letterhead or form. Letterhead must be able to withstand the fuser temperature of 392 degrees Fahrenheit. Refer to HP LaserJet Printers - Print Media Guide for more information on paper and letterhead specifications.

The most common form of ghosting results from a developer condition known as developer starvation. Developer starvation occurs when so much toner has been required to print the first image that the developer does not have enough time to pick up enough new toner and charge it sufficiently. Developer starvation will produce light ghosting.

Follow these corrective steps to reduce image ghosting:
Use a different pattern. Avoid patterns that use a 50 percent gray scale or a "dot-on-dot-off" pattern.

Make changes to the layout of the page so that gray scale patterns do not follow black areas. If possible, make dark patterns lighter and light patterns darker. Print the image in landscape.

Experiment with print density and Resolution Enhancement Technology (RET) settings.

Print a completely black page immediately in front of the page that is experiencing the ghosting condition. This black page must be part of the same print job so that the printer's gear train does not pause between the pages.

Check humidity and temperature: Low temperature and humidity can exaggerate a ghosting condition. Make certain that the printer's environment meets the requirements given in the printer's Users Guide. Light or dark ghosting caused by the developer is highly affected by environmental conditions.

Print at 300 dots per inch (dpi).


Important items to remember when dealing with ghosting issues:
In most cases of light ghosting, changing the print cartridge will not help the condition. Replacing the print cartridge, since the EP drum or charging roller may be damaged may correct dark ghosting caused by the EP drum.

Since ghosting is mainly an issue with the EP process, switching HP LaserJet printer components and assemblies will not, in most cases, correct this condition.

FROM http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?locale=e n_US&taskId=110&prodSeriesId=25478&prodTypeId=18972&objectID=bpl04071
by ScottW on Feb 6, 2004 at 9:15am Add comment
The first thing you need to do is determine if it is the toner cartridge or the fuser. The only way to do that is to stop the print inside the printer. If the ghosting is present, it's the toner cartridge. If not it's the fuser. Can't diagnose it until we know which it is.
by moe on Feb 6, 2004 at 12:21pm Add comment
On this same subject, what would be causing a marble affect in the print. Several different cartridges have been swapped, and I'm currently throwing a known good fuser in the printer to see if the issue continues. If you could give any sort of advice on what else it would be, I would appreciate it greatly.

Thanks in advance,

Aaron
by Anonymous on May 30, 2006 at 12:57pm Add comment
Did you read my reply above your post?
by moe on May 30, 2006 at 1:07pm Add comment