Abrupt complete loss (and restoration) of single channel in Epson 4900

[Jan Morales]

I thought I'd relay an experience I just had in case it might benefit others, or in case others have insights to share about it.

I am not a frequent printer and I regularly had clogs in my print head, as evidenced by nozzle check pattern prints. So a couple of months ago I took steps to increase the humidity in my printer room and began a practice of making a print at least twice a week. Under this regimen, I have gone since then without a single clog--always perfect nozzle check patterns immediately upon powering up the printer.

Then all of a sudden earlier this week I developed a stubborn minor clog in the cyan channel, always my most troublesome channel in the past. Several cleanings did nothing so I just left it in frustration. Per my twice-weekly print regimen, I got ready to print again today. I got a nozzle check pattern that was less clogged than before, but still not quite perfect, so I decided to do a normal manual nozzle cleaning. The next patter print came up with a total loss of cyan. Not a drop of cyan ink on the paper. Several normal and power cleanings did nothing. Photo prints had the expected wild coloring of a completely missing channel. I was baffled.

Then I searched the forum here and came across this thread.

In particular, the last statement by Ernst caught my eye: "Could it be the maintenance waste ink pump you refer to? The one that sucks at the ink channels during cleaning cycles when the heads are capped on the maintenance station." I knew that my maintenance tank was nearly full, but I was waiting for the printer to tell me to replace it. I wondered if that was causing the problem. I went ahead and replaced the tank, and just two power cleanings later I had a completely restored cyan channel. The nozzle check pattern print was again perfect.

I suppose it's possible I was only two power cleanings away from a restored cyan channel before I replaced the tank, but my takeaway is that if I get a clog when the tank is nearly full, I will replace the tank right then even if the printer hasn't yet told me to.

[Mark D Segal]

Jan,

Interestingly enough, when I experience clogs on my 4900, it is usually the Cyan channel as well. One wonders whether some of these printers may have had a slightly misaligned capping station, but who knows. In my case it has always been recoverable. I don't think it has anything to do with the maintenance tank. As long as the firmware doesn't tell you to replace it, you can go on using it. The main thing is to make test prints between cleanings. I would normally do a couple of regular channel-pair (C/VM) clean/print cycles, and if it isn't cleared yet, a power-clean/print cycle or two. I created a page full of Cyan and VM to handle the printing of this channel pair. I have rarely ever needed more than this. It just takes some patience and coaxing.

[Wayne Fox]

I suppose it's possible I was only two power cleanings away from a restored cyan channel before I replaced the tank,

Just had a chat with my partner who repairs epson printers. I think the two power cleans were the answer, and possibly other factors.  There really isn’t any continuity of suction or pressure to those maintenance tanks, the exit for the pump assembly and one other part simply drain there.  The pump will suck through the head and and then push the results out of an exit tube which is allowed to drain into those tanks.  But there is no seal so a full tank could cause back pressure or other problem. More like just catching a drip in a bucket.