If you own an older wide format printer model that's been manufactured a while back, sometimes the waste ink sponges have dried out between the time of production to the moment you actually bought it and got it in hand. These are the sponges that are on the very right side in the printer and you can see them when the printhead moves into the center. For this example, we're using a Canon Pixma IX6820.
When the printer is not in use the printhead sits on these waste ink sponges to prevent the cartridges from drying out. That means they are not supposed to be entirely dry when you set up the new printer. But it is possible that if the printer has been manufactured a while back, that the waste ink sponges are dried out by the time you received the printer. With regular chemical ink that is not a big deal. But with edible ink it is different. Because of this, the ink cartridges can actually dry out.
This is how you'd re-wet dry waste ink sponges and revive them:
1. While the printer is turned on, open the lid.
2. When the printhead carriage comes to the center, unplug the printer from the back. (Do not turn it off first.)
3. Carefully slide the printhead carriage to the left.
4. Find where the waste sponges are located. (See below and see step 5 to know where to find them and what they look like.)
5. Using a syringe or an eye dropper, drop 3 drops of water on each rectangular sponge.
6. Close the printer and plug it in.
7. Let the sponges soak for 5-10 minutes. (If you're not good to go by the end of step 9, you may have to add a couple of more drops to each sponge and let them soak overnight.)
8. Run a nozzle check.
9. If the nozzle check does not show clearly, run a printhead cleaning through the maintenance program and run another nozzle check.
10. If this still does not work, you may need to revive the sponges again a few more times by following these instructions again.