Inkjet printers do not have white ink. So printing only in black and white is not possible. The printer mixes the black ink with color in order to produce different gray values. The reason why inkjets and color laser printers cannot print when there is an empty or missing cartridge ia due to the fact that everytime you power up the printer, it will initiate a charging and head cleaning cycle. Running this cycle with an empty or missing ink cartridge would quickly cause irreparable damage to the print head . This is why a printer will not work in this situation. When you press the button for 10 seconds, then it may work for a short time (probably there is a little ink still in the cartridge). If you truly want only black and white printing, and not have to spend money on color inks that you will "never" use, then your best option is a monochromatic laser printer.
Where is it leaking? Depending on the location of the leak, it could be the maintenance tank is full. Or the print heads have become defective. Neither are user-replicable Given the age of the printer, these are not unusual occurrences , and can be a sign to get a new printer. The SureColor P-600https://bhpho.to/2cwHB9d is the latest generation of their 13 inch 9 ink system fine art printers.