9900: Missing all left ink bay channels

[John Caldwell]

Some time ago, Decision One replaced many parts in our 9900 including heads and capping station, and the machine has never been totally right since. A recurring symptom is that after sitting for a few days in a 45-50% RH environment, all left ink-bay ink channels are 95-100% absent on startup, while right ink-bay channels are 100% present. With repeated cleanings, often Powerful cleanings, the left side channels come fully back. But this is only to be repeated the next time the machine sits unused for a few days. Mind you, the right side inks are always fine.

What diagnosis does this point to? What is common the the left ink bay pathway that might fail to deliver ink to all channels for that side, without affecting the contralateral side?

I am reluctant to allow Epson to go through their normal process of shipping me a large box of parts, to be followed by a D1 tech that exchanges stuff without diagnosis. We've been through such methods three times on this 9900, with satisfactory results rarely. The pairing of Epson Pro Graphics support and D1 has, in my experience, not been confidence building. I'm hoping that because we have been through quite a bit of trouble with our 4900 and 9900 machines, that Epson will allow my local reseller and post-warranty service center, in whom I have far greater faith, to become involved as diagnosticians and service technologists. Thankfully, we are under extended warranty.

John Caldwell

[cybis]

This seems to point to a pressurization problem in the left ink bay. A kink or obstruction in the left pressurization line (1) is one problem that could cause your symptoms. This may have happened when the technician reinstalled the left cover. In this case the pressurization pump may be running for a shorter time on start up followed soon after (if the obstruction is partial) by multiple shorter bursts.

Another scenario would be an air leak on the pressurization side (2) but I think (not sure at all) that all cartridges in both bays would be affected by an air leak anywhere in the system as they are interconnected without check valves (not sure). This would cause the pressurization pump to run longer and more often. In case I'm mistaken and the left and right ink bays are pressurized independently (I can test this w-e, if anyone else doesn't have the answer in the meantime), an air leak anywhere in the left ink bay could be the problem – including an air leak in any cartridges in the left bay. In this case maybe start with reseating all the ink cartridges, or replacing the cartridges in the left bay one at the time.

Or, a kink in the left bay ink lines (3) (unlikely)

Or, a combination of (1), (2), or (3).

[Garnick]

Some time ago, Decision One replaced many parts in our 9900 including heads and capping station, and the machine has never been totally right since. A recurring symptom is that after sitting for a few days in a 45-50% RH environment, all left ink-bay ink channels are 95-100% absent on startup, while right ink-bay channels are 100% present. With repeated cleanings, often Powerful cleanings, the left side channels come fully back. But this is only to be repeated the next time the machine sits unused for a few days. Mind you, the right side inks are always fine.

What diagnosis does this point to? What is common the the left ink bay pathway that might fail to deliver ink to all channels for that side, without affecting the contralateral side?

I am reluctant to allow Epson to go through their normal process of shipping me a large box of parts, to be followed by a D1 tech that exchanges stuff without diagnosis. We've been through such methods three times on this 9900, with satisfactory results rarely. The pairing of Epson Pro Graphics support and D1 has, in my experience, not been confidence building. I'm hoping that because we have been through quite a bit of trouble with our 4900 and 9900 machines, that Epson will allow my local reseller and post-warranty service center, in whom I have far greater faith, to become involved as diagnosticians and service technologists. Thankfully, we are under extended warranty.

John Caldwell

Hi John,

Unfortunately I have no plausible answer to your dilemma, although I can certainly commiserate with your predicament and lack of confidence in D1 as a service provider for these printers.  My initial experience with the 9900 a bit more than 5 years ago was not a good one, but after many part replacements and extended warranties, as well as gaining knowledge about proper maintenance procedures the printer has worked well for that past 2+ years.  Of course there are the occasional nozzle dropouts and accompanying cleaning cycles(in Service Mode), but so far nothing that would require a service call.  As a matter of fact, if a service call is required I would have no idea who to get in touch with.  I would perhaps call Epson for a referral, but I very much doubt they would steer me in any direction  other than D1, in which case I would be stuck.  I dare not contemplate of that scenario.  I will say there was one tech there with whom I had a good report, but if they sent another tech they would invariably end up calling the fellow I requested originally and get information from him.  As you mentioned, certainly NOT a confidence builder.

As to your situation - have you ever tried a simple restart when this happens.  It sort of sounds like a lack of cartridge pressure, in which case a restart can sometimes overcome that issue.  Also, perhaps start up in Service Mode and do the cleaning cycles there.  I have always found the clean cycles in SM to be considerably more efficient than in Standard Operating Mode.  The only other thing I can think of is perhaps a Damper/Selector issue, but the pressure possibility might be easier to deal with and diagnose.  One thing I have learned to do is stay with the printer during startup and listen.  If one of the pressure pumps is faulty you should hear a different sound during startup.  Not as loud or as long a time for the pump(s) to achieve the proper pressure.  Just a thought, something to chew on perhaps.  Good luck with this Jim.  If you are located in Canada, please let us know if you find another service company for these printers.

Gary

EDIT:  Looks like Luc has chimed in as I was writing this, and it would seem that we are thinking along the same lines here.  Good points on his part and more suggestions to follow.         

[John Caldwell]

Thanks for your replies. I am told one pump pressurizes both bays, but does so by the connecting to those bays with two lines. So a possible unifying explanation isn't the pump, but possibly the line connecting the left ink bay to that pump.

I've also been informed that Epson is unwilling to approve any party aside from D1 to conduct the service. I dread that solution.

As for chasing the problem with more or different cleaning rituals, I'm not on board with that as a solution, as you might imagine.

Thanks for your interest.

John-

[cybis]

There is only one pump and two lines, the only thing I'm unsure about is if they are also check valves (I doubt it).
If you decide to investigate yourself (I would), just remove that left cover and take a peak at the pressurization line (pressure tube). You know that the pressurization pump is fine as it pressurizes the right side just fine.

[cybis]

So a possible unifying explanation isn't the pump, but possibly the line connecting the left ink bay to that pump.

So just to be clear, I wasn't suggesting there is anything wrong with the pump. Just that a kink or an air leak will cause the pump to compensate. In the case of a kink in the pressure tube to the left bay, the pump will run for a shorter time on startup as it will reach its operating pressure after filling only half the normal volume, i.e. only the right bay. In the case of a leak the pump will work harder.

[cybis]

Another idea to troubleshoot: it may be possible to hear the difference between the right and left bay when the system depressurizes on shutdown. On my printer I can hear the ink bags expending on shutdown. If there is a lack of sound from the left ink bay, we'll know we are on the right track.

[John Caldwell]

Thank you for the diagnostic ideas, cybis.

John-

[Garnick]

Another idea to troubleshoot: it may be possible to hear the difference between the right and left bay when the system depressurizes on shutdown. On my printer I can hear the ink bags expending on shutdown. If there is a lack of sound from the left ink bay, we'll know we are on the right track.

Interesting -- one more reason to listen.  With the various kinds of equipment I've used over many years in the photography lab business I seem to have developed a natural, and yet subliminal ability to detect certain sounds emanating from those machines, including inkjet printers.  Unfortunately, with the tinnitus progressing as it is my hearing is not as acute as it once was.  However, I still have a routine of standing beside the 9900 as it starts up, listening to the sounds I can still hear and determining if something might have changed.  I will say that I have never noticed the expanding ink bays as Luc suggests.  Oh to have young(tinnitus free) ears again .  I suppose it's much like driving the same vehicle for a long period of time.  Detecting unusual sounds can save one time and money when problems are caught and diagnosed early.  I hope you can solve this soon John.  Hopefully without the "help" of D1 !!!

Gary

[cybis]

Now that I think about it, the sound I mentioned earlier is probably not coming from the ink bags (since there shouldn’t be any air in them and ink, being liquid, doesn’t change volume with pressure changes), but from the membrane sealing the air chamber inside the cartridges. The membrane is being pushed against the inside of the cartridge and makes a sound when it relaxes after depressurization – all the same as far as troubleshooting this problem.

[cybis]

There is only one pump and two lines, the only thing I'm unsure about is if they are also check valves (I doubt it).

So I checked and both ink bays are freely interconnected with no check valves. There is a pressure switch that stops the pump when the differential pressure reaches approximately 5 psi.