I am trying to revive a 7800 printer that had been in hibernation for 4 months . Flush solution in all the lines. When I printed a nozzle check the magenta essentially did not print. (There appears to be air bubbles in the black, cyan and yellow.) . I ran 2 power cleanings and had a soaked folded bounty paper towel under the head for 2 days and then 3 more power cleanings. The problem persists.
The nozzle check is below. Any recommendations?