Canon printer can't print in grayscale.

Canon printer cannot print. Possible reasons: air intake of the nozzle, nozzle blockage, and the printer has been useless for a long time. Solution: 1. Nozzle air intake scheme: 1. Clean the print head first, generally wait 5- 10 minutes to check the nozzle, and repeat this for about 3 times. 2. Take out the ink cartridge (or continuous supply) in the printer, and you can see six black columns (when installing the ink cartridge, it should be facing the ink outlet of the ink cartridge), find the corresponding yellow column (no color can be found), insert the needle tube (no needle) above the column, as long as the nozzle of the needle corresponds to the conical part (connecting nozzle) of the column, ensure sealing, and continuously pump air with the needle tube for 2-3 times. Second, the solution to nozzle blockage: 1. Prepare 4 or 6 20ML syringes and remove the needles. 2. Do a nozzle check and print a test page to see which color is not ink. 3. Take out the built-in ink cartridge. 4. Put the ink cartridge into the printer and clean it once. Third, the solution for long-term non-use: If the nozzle is not blocked very badly, then clean it directly on the printer. If repeated cleaning still has no effect, you can remove the ink cartridge (for printers with non-integrated ink cartridge nozzles, you need to remove the nozzles, but you need to be careful), soak the nozzles in warm water for a while, and do not immerse the circuit board in water, otherwise the consequences will be unimaginable. Absorb the water droplets with absorbent paper, and then clean the nozzle several times after installation.