So I've hit the dreaded failed head issue with my Epson 4900. I've gone through the Piezo Flush routine numerous times, tried the Windex routine, and done multiple regular head cleanings, all to no avail. Consistently nothing coming through any of the nozzles when doing a Print Check Pattern on either the LC or VLM channels. In fact, despite having run the Piezo Flush through three or four times using the initial fill program in the Service Program there appears to be no change in the level of the Piezo Flush in those two cartridges (LC and VLM). I'm considering using this printer for Piezography and there seems to be indications in various threads that even with two channels down you can remap the channels so QTR will function properly. I want to make sure this is correct before spending the money on the additional cartridges, inks and software for Piezography. I'm also interested to know if anyone else has done this successfully with this printer model after having had failed channels. Since two channels on the print head have failed, is it likely others soon will also (the printer is about 3.5 years old)? Any advice on this would be helpful. Thanks!