Why is this printing oddly?

[dgsmith]

Got a HP Colour laserjet 5550 which when printing photos (which blends toners) they don't look right at all. I did a test page with single colours and blends and the output was as attached.

 

Single colours print fine (although the cyan is darker than it should be), yet further down the bottom, the blends look nothing like they should! In order, it should be cyan-magenta, cyan-yellow, magenta-yellow.

 

The black is a bit faded towards the right but I am not worrying about that too much for now.

 

Obviously yellow is fine as it prints as expected on it's own bit looks orange on the blend. Is there something that needs to be done or a reason this could be happening? I have reset printer to defaults in case someone had faffed with it but to no avail!

 

[plexer]

I'd change the knackered black toner and see what it's like then.

 

Ben

[JonThompson]

I'd change the knackered black toner and see what it's like then.

 

Ben

 

I'd second that. I'm leaning towards the fact that there is not enough black toner left to blend the colours effectively.

[dgsmith]

Thing is it happened (with the black) on the previous toner which we changed when it was still at 40%, yet it doesn't seem to have improved, so I am leaning towards another issue but these printers are so large I wouldn't know where to start looking or what to check/try first!

[plexer]

If they are like the other HP printers what do you get when you run the print quality troubleshooting from the control panel?

 

Ben

[plexer]

HP Color LaserJet 5550 Printer series- HP Color LaserJet 5550 Series Printer - Image Formation Troubleshooting - c00230735 - HP Business Support Center

 

Ben

[Zourous]

Have you tried changing the cyan cartridge as this is the one printing darker for no good reason?

[dgsmith]

Haven't got any spares for this (we only buy as and when needed), however the toner powder is clearly actual cyan in colour thus I guess something is happening in the printer to make it go darker (or it's mixing with the black).

 

I can see on the blends that it's distorted towards the right which is where the black also fades too, but why would the yellow need any black at all?

 

I don't want to go out and buy new toner (which we can ill afford) if the issue lies elsewhere, and hoped maybe someone with perhaps some decent knowledge of printers (or this model) could offer some diagnostic suggestions?

[Zourous]

What I've done a few times is to stop the printer whilst it is printing by opening a door. Sometimes if you catch it at the right moment, it can give you a clue to where the problem is. The pure cyan from the toner must at some point by getting mixed in with something else. See if you can catch it the moment it hits the page, and if that is ok, then try and catch it just after that the next time round. Also try not to get too much toner on your hands as the toner won't be fused at this stage

[plexer]

If you run through the troubleshooting I've linked to it will help show if the issue is related to one colour or another your test sheet doesn't really help identify if there is one colour that is causing the issue you need to print separate black, cyan, yellow and magenta pages.

 

Ben

[dgsmith]

Quality diag pages did show issues with black and small issue with cyan, but none the less changed both and now it's fine. I guess I just assumed it was a more complex issue but glad it really was as simple as that

[sparky2488]

Old Post but most likely from poor drum earth.