There are many reasons due to which you can find Canon Pixma MG3620 printer not working. It can due to connectivity error. Make sure that the printer is connected to a Wi-Fi network. The computer and the printer must be connected to the same Wi-Fi network. The nozzle and print head of the printer might not be clean. Clean you printer thoroughly. There can be stuck printing jobs in the queue. Clear the queue. Check if there is enough ink and toner in the printer.