I cannot print, How do I fix this?

Thank you for your question. My name is Umair and i will be assisting you with this issue. This error usually results due to resistance in the cartridges. The silver bar that your print cartridges glide back and forth is most probably causing the problem. When the motor that moves the cartridges left and right have too much resistance, you can get the hardware error 0502.
Take some kleenex, and with power unplugged, clean the bar very well. Then Spray some WD-40 on a Kleenex, and lubricate the shaft. This should eliminate the resistance between the cartridges and your printer should work fine.
Please let me know how it goes. I will be waiting for your reply. Thank you.

Thank you for replying. Please follow the instructions by clicking HERE. Make sure you have performed all the steps carefully and check if it works. If it still doesn't work your printer might have to be sent to your nearest Service Center. Please let me know how it goes. Thank you.

It appears that your encoder strip has misplaced and that's why you can hear the clicking sounds. You need to re-adjust it by following the steps given on the link that i have shared with you. Please try these steps and let me know how it goes. Thank you.

Thank you for replying. I am glad the error is gone now and yes you are good to go. To replace old cartridges with new ones, please perform the steps below:

1-Make sure the machine is on.
2-Lift the printer (scanner unit) until the scanner support keeps it open.
The ink cartridge carrier moves and stops at the loading position unless the All-In-One is busy.
3-Squeeze the tabs on the cartridge lids, and then lift the lids.
4-Remove the old cartridges. Store them in an air-tight container or dispose of them.
5-If you are installing new cartridges, remove the stickers and tape from the bottom of the cartridges.
6-Insert the new cartridges, and then snap the lids closed.
7-Lift the printer (scanner unit) and push the scanner support back while lowering the printer (scanner unit) until it is closed.
8-Load paper into the paper support.
9-Questions appear on the display. Use the buttons on the operator panel to answer the questions:
(A) If the color cartridge you installed is New (never been used), press Select.
If it is old, press +, and then press Select.
(B) If the black cartridge you installed is New, press Select.
If it is old, press +, and then press Select.

Please click on the Green "Accept Answer" button to acknowledge my answer. Thank you.

The Low-ink message shouldn't appear if you have installed the new cartridges correctly. Please follow the procedure i have given above. Thank you.

I am glad it's working fine now. Thank you.