From doing my research, I have found that the 50C Error message comes from the cartridge, usually if it has been refilled. If this cartridge is new, please return it to the place of purchase for a new one or a refund.
If you unplug the printer from the wall and remove the power brick for 60 seconds, this will reset any error message the printer has. Then power on the printer and open it up. Try taking out the black Dell Series 2 ink cartridge and reseat it. Do the same for the color cartridge. Close the printer and it will try to print an alignment page.
Any error messages?
black cartridge = black side(left side) color cartridge = color side(right side)
Photo cartridge = black side(left side) color cartridge = color side(right side)