My husband and I just bought a used Epson 7600. It had been sitting for awhile, so I purchased some Piezoflush from Inkjetmall. I've done a number of power-cleans, and all of the cartridges have flushed out except for the magenta. The flush doesn't seem to be making its way through the magenta ink-piping at all, and the nozzle checks come out completely clear (meaning, no ink is printing whatsoever).
Any ideas, hints, tricks?