Can you pls tel me how to resett ink cartredges for hp deskjet (F2420)

This should help: Help Installing Your HP 301 Ink Cartridges and Error Troubleshooting...

Pretend to replace all the ink cartridges all over again, with all on, then go into the Control Pannel, Hardware, Devices & printers and make sure you don't have to run any maitenance services (ink-head allignment, roller cleaning,ect.)or verify via properties that you have replaced the cartredges.

U must be using HP74, 75 cartridge for your printer.

There are few reasons you are getting black and white (gray)...for printing job.

1. No color ink.
- If you are out of color ink.. that's what it happens.
- check your ink level through control panel.

2. Printer set up. (I think this is pretty much the reason you are not getting color)
- First, check your printer setting.
If they are on gray scale mode, pls chang to color.
How? when you click the print (through file manu), there are option for control panel on your screen. Click that option and will see some detail option you can choose from size, print quality.
Among the print quality option, pls choose, color mode instead of gray mode. That's it.

If you would like to save money, try refill kit by "ROADINK".
Not only they are easy, but also the printing quality is good.
For your better understanding pls check out my youtube video.
And will see how easy ink refill can be done.

hello

the problem of your printer is the mechanical board try to switch off for the moment and turn back on, remove the plug form the wall outlet. leave it off for 5 minutes.


thanks

Specific! for your model,or refill.

If any more problem encounter,post or thumbs back.

Here is what I found on the Web. You can click on the link below, to see Full Instructions. If you find this helpful, pls rate me.

http://h10032.www1.hp.com/ctg/Manual/c00687555.pdf

View estimated ink levels
Follow these instructions to view the estimated ink levels of the print cartridges that are installed in the printer:

1. Open the printer Toolbox.
2. Click the Estimated Ink Level tab.

Note If the print cartridges were used before being installed in the printer, the
estimated ink levels will not appear on the Estimated Ink Level tab.
The Estimated Ink Level tab also contains print cartridge ordering information. To view
this information, click the Print Cartridge Information button.

Thanks and good luck.......
Pls rate me

You will need the correct cartridge for your printer to work properly. If you can't locate the proper cartridge find an ink refill kit and refill your old cartridge.

try reinstalling the printer.

The Deskjet 6940 will only show ink level for original HP cartrdgies. Refilled or reman cartridges will show as empty or unknown in the toolbox. This is not an issue with the driver, the cartrdige itself has information that it has been previously used and this is not resettable. You can continue to print with a cartrdige that has unknown ink levels, you will just not get low ink warnings.

Regards,
Bob Headrick, Micosoft MVP Printing/Imaging

Not sure what o/s you are using, but try to visit below page .. ihave put some summary to this issue.
http://etech.maiila.com/?p=14