HP color laserjet cp1518ni Printer was printing fine in all colors, but today it is not printing blue....even demo is missing the color. I checked the toner and it is only half full. I have tried cleaning the printer and calibrating color (service options). Please advise...thanks

Hi there, my name is Lisa and I'd be happy to help you with your LaserJet CP1515n. The following document will help you to troubleshoot the issue you have described:
HP Color LaserJet CP1215 CP1217 CP1514n CP1515n and CP1518ni Printers One...

I took a second look and found this one too:

HP Color LaserJet CP1514n CP1515n and CP1518ni Printers Resolving Print...

I hope this helps.
I work on behalf of HP.

Hi, Try re-installing the printer driver and see.
Hope it works,
cheers, K

you need new ink if not used it will dry up. if you are not sure go buy black ink

Try this, if not contact HP https://support.hp.com/us-en/drivers

two possible problem:-
1. Check cable connected with printer and 2. driver of printer must be deleted or corrupted, re-install drivers..

It's possible that the toner in the cartridge is not evenly distributed. You can redistribute toner if you gently shake the cartridge from side to side, then reinstall it to see if this affects performance. Please also see this article.
You might wish to use the guided troubleshooting option available from HP support here. Or have a look at the troubleshooting section in the user manual here. Then clean the engine & calibrate the printer, as described pg. 88.
If that's no help, please see this forum post and the linked attachments within.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!

printer is ok, check the connecting cable and drivers.

Possible causes
Bad Print Drive
Remanufactured Toner Cartridges

Print a Demo page from the Printer Control Panel. You do this by pressing
Menu
Computer Information
and then select the Demo Page and press the Green Key to select that choice

light printing

Don't ever use compataable cartridge for printing .
(1)Check for printer sleave damage....
(2) check for any noise from printer when printing noise from fuser section.
(3).. Print a Demo color level page ...
(4)Check for scaner section ......

Thank you.