My black ink cartridge was low, I replaced it and now the printer won't recognise that there is a new cartridge in the machine.

This will either be because your printer is having trouble recognising the cartridges or warning of low ink because the cartridges have been refilled. Connect a computer to the printer and it will hopefully give you more info.

If your printer cannot recognise the cartridges try wiping the contacts on the front of the cartridges and re-installing. If your printer still doesn't recognise the ink cartridges then sadly they will need replacing.

If it is just a low ink warning then carry on printing untill the printer thinks the cartridges are empty and prevents you from printing. You can them get around this message by pressing the stop/reset/resume button for 5 seconds and continue printing. More information on this can be found here: http://www.refreshcartridges.co.uk/igloo/the-infamous-canon-resumestopreset-button/

Hope this helps.

Follow this link may be it will help you....http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=buu01850

When replacing ink on the Epson Workforce 520, Ensure the cartridges have the correct/same number of gold contacts. Ive seen them with 7 and 9 gold square contacts and they were otherwise identical, and the ones with 9 contacts threw an "cartridge not recognized" error on the printer's dispay.

Your machine needs to be serviced.
replace the cartridge with the original one.
it can not print if one cartridge is missing or not original.

You might have to uninstall and reinstall your printer on your computer hope this helps Merry Christmas

I think you purchased a black cartridge with bad electronics. Basically your cartridge can't communicate with your printer and you should exchange it for a new one. There is no way to "fool" your printer into accepting refills with bad electronics. What you can do is when you get the message that you aren't using genuine cartridges and it won't be able to estimate ink levels is to check the box indicating to ignore the ink levels.

It mean that the black cartridge is not recognised. It the black cart is original or compatible? Some printer won't recognise cartridge, if the black and colour is not same type. Try to install the black only. Is it recognised?

replace cartridge, take the cartridge back to get another, this is a common issue.

This machine is not meant to switch between the two black cartridges. The large one is used when you are using black only, and the small one is used when you are printing in color.

Using replacement cartridges that come without a chip seems to be the problem I had with the Canon Pixma 510 printer they are cheaper
but if they do not show the ink levels then its inconvienent so I have but Canon products with a chip and they work perfectly.