Doing this test without a good nozzle test is a waste of ink. Missing nozzles you can expect banding and wrong colors.
Without being there and know what got it to that state it is hard to say. If it was not plugged in and ink removed, then you have the head clogged with ink. If a 48hr headsoad did not move it or moved the ink enough, then maybe another 48 hours. The quickest way to correct is to replace the head.
From where I sit, the quickest and most efficient option are new heads.