Unfortunately, I just had another occurrence of a dead printhead with my Epson 3880, which manifested itself in an identical way to that of my Epson 3800 about 4 years ago.
While I decided to trash the previous 3800 printer by sending it to an electronics recycling company, this time I decided to get it repaired. I knew that changing the printhead would cost about $500, so I thought it would be worth going this route…
Not so fast! The Epson recommended repair shop first replaced the pump assembly, which together with labor, cost $240. I thought that it was the end of the story and was happy to end this with a rather inexpensive repair. Unfortunately, as soon as I brought the printer back home, it was showing the same leak symptoms (leaky Photo Black nozzles, emptying the PK cartridge in less than a day simply in standby mode !!) I brought it back to the repair shop, which acknowledged that the problem was not as simple as initially thought (duh). On my side, I knew all along that the nozzles were irreparably damaged, and yes, they admitted that a new printhead had to be ordered. I went along, but soon regretted going through the whole thing because the total for replacing the printhead was not only $463 (without labor, which they gave for free), but I had to give them several new ink tanks at my cost to refill the lines and printhead. Overall, the total cost was $1,110. A new printer as of 8/7/2014 is $1,129, but there is a $200 Epson rebate for this printer right now!
Clearly, this shows that it makes absolutely no sense to repair your printer if your printhead shows the same symptoms. From the start, I had already wasted 2 ink tanks on it by not seeing the problem right away (each tank costs ~$55). If you get this problem, you might as well say goodbye to your printer!
Finally, this problem appears to be a general one with all inkjet printers using pigmented inks, according to my contact at Atlex. The Epson 4900 is even worse, and the Epson 3880 seems to be relatively reliable. Canon printers have similar and other issues, but the printheads of those can be changed by the user, although they do not come cheap either. The technology behind the nanosized ink particles in all pigmented inks is amazing, but these inks are prone to dry in the nozzles when the printer is not used at least once a week. This can irreversibly damage the print nozzles. For this reason, make sure to run a weekly printout through your printer to keep the heads clean and the cartridge tanks shaken, which avoids the pigmented inks from settling in.