I had exactly the same problem - "7 orange blinking lights, then one green"
According to user manual, this indicates defective print head. The print head had clogged so deep that can not be cleaned in the normal way. The printer can not communicate with the computer at this point. So you can't send the cleaning command to printer.
Here's what I did:
1. remove all the ink cartridges
2. Take out the print head by release the gray lock lever. Look in the "Easy Setup Instruction" Step 3 to find the location.
(You can download it from Canon USA web site)
3. Put the print head in a plastic zipper bag. (Test the bag is air tight. I used a Freezer bag)
4. Soak the covered printer head in hot water (hottest setting of the tap) for 5 minutes. The high temperature will soften the clogged ink.
5. Immediately install the head (should still be dry) in the printer, and install all the ink cartridges.
6. Turn on the printer. If this works, you should not have the "7 orange blinking lights". Then you can start the cleaning process from the computer. Run the cleaning several times or deep clean it.
Luckily, this worked for me.
Good Luck!