My HP officejet Pro L7580 doesnot print in black but I can print other colors. What could be the problem. Please help

It's probably a problem with the black/yellow head.
lift the topup to access the heads. if the heads don't move over to the change station area (all the way left as I recall for that unit) press and hold the * until they do.
lift the big blue flap, then the blue handle on the black/yellow head and pull straight up to remove it.
Take a q-tip dampened with bottled water (dampened, not dripping) and clean the CONTACTS area (not the HEAD, just the little round/square copper pads) on the printhead, and disconnect the power from the printer, and clean the printhead contacts in the printer as well.
Without reinserting the head, close up the head access blue flap, and close the printer lid
press and hold the # and the 6 on the keypad. While holding these, reconnect the printer power
wait for a RESET message of some form to appear on the screen, or for the printer to shut back down.
If the printer demands you replace the damaged/missing head, put the printhead back in at that point, but not unless the printer is asking for it!
Once you have released the buttons, turn the printer back on if it shut itself back off.
put the printhead back in when the printer asks for it, if it hasn't already.
The printer will now go through several minutes or whirring and clicking and so forth. Let it.
In the end, it should produce a calibration page.
If the black prints ok, you're done.

If not, you'll heed to replace the black/yellow (K/Y) head.
You can usually get them where you get your ink.

You would be surprised but it's probably the problem with magenta/cyan color. It's a common problem so check out this cartridge first, then reset the printer. If everything fails try to reinstall the drivers and read the users manual