LJ5550 Toners...

[DavidM]

Is it possible for a HP Black Toner Cartridge to cause multiple printers to no longer recognize an 'Original HP Toner'? We have a new HP black toner cartridge, that after it was placed into two LJ5550 printers the printers now say that the any toner installed is not and HP toner. Even when I tried a third (known good toner) from a different printer we still get the not HP toner on both of these printers. I now have two printers that won't recognize any black toner as HP originals. I'm afraid to try it in a third one. Is it possible for a toner to damage the sensor in the LJ5550 printer?

David

[Big Al]

I have seen quite a few genuine HP cartridges where the chip on the cartridge did not work and it complained of a "Memory Error." If this chip is shorted then it may overheat/overload/damage the circuit that talks to this chip. The chip just sits on the cartridge, it is not connected to anything in the cartridge. Previous posts seemed to indicate that this condition would go away when a good cartridge was installed but I have not seen this myself. You might want to flag this cartridge so it does not migrate into other machines. We get some recycled cartridges with a cloned chip that the printer thinks is a genuine HP unit, and some with no chip at all. These complain about memory error but you just have to push the green button with the check mark and the printer is OK until you power it down. Interesting situation. Let us know what you find. Might want to push this up the line with HP support. Is this printer still under warranty? HP should replace this cartridge, they guarantee them.

Al

[DavidM]

Ok, I got a brand new toner and tried it in one of the printers and it now says to clean the Fuser Input and Replace the Black Toner Cartridge. I tried cleaning the Fuser input with the brush on the door and that didn't clear the message so I blew it out with a can of air too. The message remains the same. I then tried the new toner in the other 5550 printer and got the same message, even after I cleaned the fuser input. I checked the new toner cartridge in a third 5550 printer and it worked fine. Also, both printers have a question mark in the black toner on the LCD display.

[Big Al]

In these printers the laser beam goes through lucite light pipes to get to the image cylinder in the toner cartridge. A little toner on these windows can really mess them up. A really good bath in compressed air sometimes does wonders. The canned gas is not quite as good here. Not sure how this affects the other issues you are having with the cartridges. Look for the clear windows that carry the laser light and clean them well.

Al