Epson 7900-Need help after replacing the Damper unit.

[Mr2xfour]

Ok, my test prints were coming back with Photo Black almost non-existant.Numerous cleanings, wiper exchange,  head wipes with PiezoFlush and Magic Bullet and capping station and flushing box cleanings later, still no change. All the other colors were present and complete on all nozzle test prints. I read of ink starvation and that dampers should be replaced every 1-3 years. Seeing the cost of a head, the damper unit was by far more cost effective for me, it was obvious which replacement would be 1st. So, armed with an excellent video from Eric,at My X900.com. yesterday, I replaced the damper unit and chain seals that I got from Compass Micro. Now, The last thing Eric mentioned were  cleanings in pairs, which I did, but after seeing my 1st test prints come out completely blank, devoid of any trace of color, it then occured to me that Eric was speaking in terms of a head placement, not damper unit. So, scouring the Service and Fields manuals I found that Power Cleanings needed to be done after a damper replacement to introduce ink into an empty damper.  So I did 2 Power Cleanings, and I did see a faint image of photo black, but the other colors were still non-existant. Should I perform more Power Cleanings? Grasping at straws I cleared the counter for the Ink Selector to see if that would help... it didn't.  I must mention that before the Power cleanings I intitiated an Init.Fill thinking that it would fill the lines with ink, because after installing the damper I noticed alot of air in the lines.I was also wondering if the 3 ribbon cables and 2 electrical connectors on the damper could have been installed incorrectly, I doubt it, but there's always that possibility.  Well, there it is, I'm hoping someone with more knowledge than I will know if I either did something wrong, or did something in the wrong sequence or if there's something I still need to do. I've had to shut it down until I order more ink, all the cleanings drained my cartridges like it was nobodys business! Any help, thoughts, pearls of wisdom that anyone would mind sharing with me regarding this problem would very much appreciated! Thanks in Advance!

[langier]

Had my 9900 serviced last week. First time as the second owner...

It's gone through a pallet of canvas and hundreds of feet of paper and was beyond time to do it. My tech came and did it replacing the entire pump unit. The previous service for that part was dated Sept. 2009. He cleaned the head and got it running, but the Light Black had a few nozzles that were misbehaving...Waited a few hours and still had gaps and lines. Did every cleaning, both global and pairs and still not firing... So with nothing to loose and knowing the next step was head replacement, I pulled it apart.

Since I did not have any cleaning solution, I licked a link-free wipe and cleaned the head a couple of times. Did a nozzle check and the problem was gone. Ran a cleaning cycle and it's now printing just fine.

If all the fancy treatments aren't working, this may do the job. Remember, YRMV and you may be still looking into head replacement, but this may solve your problem.

[Wayne Fox]

If you’ve already run an init-fill as well as two power cleans with no results, it seems there’s an electronic problem going on.  The cables are certainly one, they can be finicky and even though they might seem they are in correctly, it’s possible they aren’t. So I would check there.

When you do a power clean or init-fill with the side panel off, watch the exit tubes and verify ink is actually flowing out. You can also watch individual lines if there are little air bubbles and watch to see if they move.  If no ink is moving through the machine and the cables seem OK, make sure you haven’t accidentally disconnected the pressure lines that are used to pressurize the ink cartridges  They are two plastic tubes from the pressure pump and one runs into the back of each ink bay..  If they aren’t pressurizing, you won’t get ink flowing.

Good luck.  We’ve replace a lot of damper units over the years, and really never seen an issue where this happened that wasn’t explainable by something we did wrong (we’ve shorted out one mother board over the years, not sure it was when doing a damper replacement as we’ve also replaced quite a few heads).

[Mr2xfour]

Thank You for the advice! I've been away from my patient for a week, but I will definately open her back up to revisit the the electrical connections and check the pressure lines, as recommended, this weekend. Sure hope I find something, really not crazy about having a rather large, expensive "paper-weight" commanding a good-sized footprint in my printroom! Thanks, Again!

[Mr2xfour]

Okay. I rechecked the small yellow and larger white connectors and the pressure line,of the damper unit, disconnected and reconnected them. Pressure line was connected.  Removing the yellow connector was difficult, and in the process when it did disconnect I noticed the 2 pins had bent slightly downward. I pushed the base of the connector up and back against the board to straighten, and inserted the connector. Not so much a problem with the white connector. I did the same with the 3 ribbon cables. I did have a hard time to reinstall the ribbon cables as one side would push in while the other side almost would not go in. I tried to install as gently as I could but some slight bending did occur when they finally went in. I'm less sure they went in correctly this time than I did the 1st time I did this.
I then put everything back together except the side-cover, to view the ink lines while it was powered up.  But when I went to power it up it only powered up momentarily, showing the Epson logo and a few more display screens then it just shut down. As though I pulled the plug from the wall.  So I thought maybe there was a microswitch somewhere that the sidecover triggered when it was installed. Didn't find one, or maybe I missed it, so I put the sidecover back on and attempted to powered it up, only for it to do the same thing, which was shut down not even a minute after pushing the power button. Could I have damaged the ribbon cables? And if so, are they something I can order/replace? I see on the Service Manual they are called "Harness, Head,A" and "Harness,Head,B" (ref.parts 524 & 525), no reference is given for the 3rd ribbon cable located to the left of the these two cables. OR, is the power issue a result of the "bent" yellow connector?  Oh and by-the-way. last week when I attempted this the carriage would move back to the home position very shortly after power up. This time it did not move at all when I powered it up. Given the time it would have taken the printer to power down I think the carriage would,at least, had the time to get back to the home position. So if anyone can show me the way of my errs I'd really appreciate it! Thank You!...again!