After two weeks of no use, I checked the head on my Epson 4900. The print pattern had a lot of the typical patterns of clogged nozzles. None were badly clogged, but about five of them had an issue. Note that the LK pattern was perfect-no missing lines. So, I tried an all channel "powerful" clean. Partway into the cycle, a low ink message appeared, along with a menu to cancel or continue, with continue followed by the word recommended. So, I went with the recommendation to continue and I replaced the low cartridge, the LK, after the cleaning cycle. Now the test pattern for everything but LK was fine, but LK went from being perfect to totally blank.
I connected to my copy of the service program and performed an ink flush. The test pattern for the LK channel was blank. I thought that something might be wrong with the cartridge, so I bought a new one. LK was still blank. Having read about the C2 cleaning level in the maintenance program, I've done four C2 cleaning cycles. The ink on the second new cartridge is now down to 85-90%, and still no sign of life.
Should I continue trying to pump ink? Does anyone think this could be a clog rather than an air lock? If so, what cleaning method should be used? Their are some warnings on the web about the C3 cleaning cycle overheating the head if there is no ink flow. I suppose ammonia cleaning could be tried first. But of all my experience with clogged heads, I've never seen one go from 100% to zero % in five minutes, and am skeptical that this is the issue.
Is it possible that I burned up a nozzle by taking the Epson recommended action to continue with the on-board "powerful cleaning" while the LK cartridge was signally low ink?
Thanks,
Jimmy
