my Canon Pixma mg7720 is printing out blank pages

[wolfselzer]

I printed out a picture one day and it came out beautiful in color five to six hours later I tried to print out something ells and all it would do is print out blank pages all the ink cartridges are practically full as I recently had changed them I clean the inkjet heads with the deep cleaning option but still blank pages come out. on the day I try to print for the second time pages came out blank and it said some kind of error and that I needed to take it in for service I'm using a Windows 7 64 bits laptop never ever had issues until now i can not afford a new printer i am broke what i can i do to fix this I hope it's not complicated to fix i need to print out some pages so can you please help 

[Patrick]

Hi wolfselzer,

Please turn your PIXMA MG7720 on and attempt to print.

What is the error code that appears at the top of the display of your PIXMA MG7720?