BLACK INK NOT WORKING

It could be the print setting on your computer.
If you're using Windows, with your document open, go to File > Properties/Preferences. In the Print Setup tab, make sure to select "Print using all available ink" in the Ink Use section.
On Mac you can select Color in Print Setting in any expanded print dialog.

Replace the colour ink. Some printers mix-in a bit of coloured ink, when printing "black", in order to prevent the colour-inks from drying-out.

You might find that it is either printing the colour parts and not printing the black parts or it is printing the black parts but not the colour parts.

In this case you need to replace the ink cartridge that your printer is not printing. Either black or colour.

Ensure to get the exact same ink cartridges so that they work 100% in your make and model of printer.

All the best!
damnor01

Many printers always use a small amount of each color even if you are only printing black, to prevent the color nozzles from drying out and getting clogged (and, it forces you to buy more ink, which is a profit center for printer manufacturers)

For this reason, some printers will not work if ANY of the cartridges are empty.

It should work again if you replace the color cartridge. Make sure to select "black ink only" or the option to print in black and white or grayscale to minimize color ink usage. It may still use a little, but that's OK.

Many printers especially Photo ones also use colour even when printing Black. so you do need to replace the spent colour cartridge.

If you only need to print in black get a B&W printer not a colour one.

replace print head assembly

You probably need a new purge assembly, it draws some ink to both clean and prime the printhead. When it stops working you won't get any ink to the paper.

Hi, this is not a solution because I don't think there is one apart from buying new inks. Epson and all other inkjet printers do this to prevent the coloured print head nozzles from getting blocked. If they are not used for a long time the ink dries up and blocks the nozzles. Epson recommends printing at least once a month with all colours to prevent this. Printing in black only option will only work if the colored inks are OK. Whenever the printer is turned on it performs a head clean, this is why the coloured inks get used over time even though they are not used for printing.

Yes you have to have ink in all of them. No, accordign to Canon it wil not work without them. 

its ok I solved it! I didn't realise that all the photo cartridge does is gloss over the colour picture produced by the colour cartridge. I simply had to replace the colour cartridge which had run out, so now its all working perfectly!!