My HP Deskjet 6540 doesn't print the test page or anything else.

Does this link to an hp.com troubleshooting page help you at all? It addresses the failure to print a color.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00219782&tmp_task=solveCategory&cc=us&dlc=en&lang=en&lc=en&product=357211

Good luck to you!

Your Printer head need cleaning, try doing a self cleaning or change you ink, hope this helps.

Have you tried printing a test page?

Please check your ink cartridge. If it is old change it. Also clean the nozzles. After doing this print the test page.

The HP Deskjet 6540 series printer has two print cartridge status lights. The left light corresponds to the left print cartridge, and the right light corresponds to the right print cartridge.

I forget but it depends on operting system you can go to this web page and look at product overview and you will see it.
http://h10061.www1.hp.com/ccsearch/search?pname=HP+Deskjet+6540+Color+Inkjet+Printer&opname=HP+Deskjet+6540+Color+Inkjet+Printer&qry=memory+size&method=prodFinder&enc=UTF-8&ctry=us&lang=en&dlc=en&sni=357211&search=0&submit.x=0&submit.y=0

You can print from your laptop to your printer wirelessly using the HP Smart app. This video shows you how:

ok, most likely your printer cartridges are off. In order to fix this, you can use windows to align them. Click start > Control Panel > Printers and Faxes, and right click the printer thats giving you trouble. Then go to properties. Next, go to the services tab, and click align the cartridges, and continue from there.

Yeah, the only thing that can cause this is paper feed problems.

There must be either something loose in the paper feed mech (look for wobbling "tires") or there is still some paper or other foreign debris in the paper feed path.

hmm...maybe your print drivers went off line?

remove them, and go here for a fresh set

happens sometimes from power glitches