On an HP PSC 950, I'm getting a repeated "Press Enter to Align Cartridges" message when I try to copy. Got a response from a previous expert that wasn't even applicable to this model, and no response when I asked for another answer or expert..

Hello, the reason your printer is constantly trying to align cartridges, is it did not complete the alignment, machine must complete alignment, so this message will go away, this machine requires all #15 black ink cartridge and #78 color ink cartridge, it requires the color ink to be working since it uses either yellow or magenta ink for calibration,also black ink has to working for this to work. now if the ink cartridges are known good ink or printing ink cartridges, then the problem maybe the sensor that detects the color when it prints, you may try with a soft wet or damp paper towel, when cover is open as if you are replacing the inks, unplug printer from power, move carraige to left alittle bit more, on the right hand side of carraige, you might see a black piece of plastic, behind that is the sensor, use the wet towel and wipe the bottom part of carraige and sensor, do this several times. now go ahead and close machine and power up, see if machine will pickup paper, print the calibration page. if all is working it should pass.

I am not an expert, what i would try is to remove the printer cartridge and reinsert them again and then use the align function.