08-29-2012 02:44 PM
I have a Designjet T1100 that is dragging the printheads on the media, causing streaks.
At this particular client site, they use only two types of paper, both of them on the roll rather than sheets: HP plain (lightweight) paper, and HP Universal Photo Gloss paper. The printer will print normally all day long with the light plain paper without error or leaving streaks. It's only the heavier Photo Gloss paper that it leaves streaks with.
I recently changed out the belt and tensioner assy, and it wasn't until after I did that that the problem emerged. Prior to that, so they say, they'd been using the Universal Photo Gloss rolls without any problems whatsoever.
Since that time I have replaced the print carriage and service station with new (from HP) parts. I've also tested printing with a brand new roll of HP Universal Photo Gloss that I myself unsealed from its box, to eliminated the possibility that the paper had been out and exposed too long, and humidity was swelling the paper and causing it to buckle into the path of the print heads. The paper rolls are sealed inside plastic bags within their retail boxes, so presumably my opening a new one eliminated exposure to humidity as an issue.
I have also made absolutely sure that I have selected the correct paper type in the printer's setup when I load the paper.
The odd thing is that if you force the printer to raise the print heads by choosing a heavier paper (such as the Coated Superheavyweight) it will pick up the print heads and print on the Universal Photo without leaving any streaks or other errors. So the problem doesn't appear to be a mechanical one, as in hardware error or damage, it appears to be that the printer is simply dropping the heads when that particular paper is chosen rather than picking them up to the higher (correct) location.
I've been told to adjust the height of the print heads. But so far as I can tell, there is no mechanism by which to incrementally adjust the height of the print heads on this model. I have seen references to it on other models, but not this one. So far as I can tell, this model has only two print head heights, low and high. This is controlled by a switch located in the top of the print carriage. When the switch is shifted to the right, the print carriage drops to the low position. When the switch is shifted left, the print carriage raises to the higher position. This is controlled by the PPS (Pen to Paper Space) solenoid, whose sole purpose is to drop a plastic finger into the print carriage to interface with the aforementioned switch and move it right or left. I've operated the printer with the right cover off so I could observe the workings; loaded the Universal Photo Gloss paper, selected same in the printer's setup, and watched the PPS solenoid hit the switch and drop the print carriage to the lower position.
Has anyone ever seen this before? HP themselves are telling me to simply have the end users select the Superheavyweight paper rather than the (correct) HP Universal Photo Gloss whenever they load that paper, and they can print with no problem. But my site contact there is a tech guy (not a bureaucrat) and he is--rightfully, I think--not accepting that as a solution. Most of the users are teachers (this is a school) and when they load paper they're going to simply set the printer for whatever paper the box says, no matter how many times he tells them to do otherwise.
Could the problem be with a logic board that controls the movement and position of the print carriage? Per HP's suggestion I also updated the firmware of the printer, though it already had the latest version. HP told me that the firmware contained various paper profiles and could have become corrupt, so replacing it might correct the problem. I did so, and it the problem remains. Is it possible to go in and edit the firmware profile for that particular type/designiation of paper?
I would be grateful for any information or guidance anyone here could offer. Thanks.
08-29-2012 02:46 PM
08-29-2012 02:53 PM
I'm wondering if when you had the carriage out to replace the belt, if you possibly removed the carriage bushings to clean them and installed them backwards? I have never had to pull a carriage on that model yet so I'm not sure if it is similar to other models where you can get the bushings in the wrong way and then you have carriage problems.
08-29-2012 06:01 PM
I do appreciate your taking the time to answer, but I did not remove any bushings. The carriage that's currently installed is new, and was installed as an assembly, as it came out of the box. I still have the old carriage, and I just examined it. The bushings only come out with the removal of a couple of screws and retaining brackets, and I didn't do anything with them on the new carriage when I installed it. I have to think that if I had installed the carriage (or some other part) incorrectly, that I'd be seeing problems with printing across the board, not with just that one particular type of paper. As I wrote before, the plotter prints perfectly with the thinner paper, and prints perfectly on the thicker photo gloss paper if you force it to raise the print heads by selecting the heaviest paper in the paper load menu.
Thanks again for taking the time to reply. If I ever find a solution to this problem it will be because you and people like you took the time to consider my difficulties and then comment.
09-04-2012 07:43 AM
Kind of a shot in the dark but, I have noticed when removing and reinstalling carriages for belt replacement on those models, it is very easy to catch the small clip on the upper back side of the carriage that controls the adjustment you are referring to. I realize you have since replaced the carriage with a new one but its possible that one got messed up to. It seems that when your lining up the second bushing on the slider rod is right when that clip on top wants to catch the upper rail as your sliding the carriage in and either break or snap off or both.
09-04-2012 02:46 PM
Well, that is something I will check. I hadn't even thought of that. As I said before, I don't believe it's physical damage of any kind, because the printer seems to be able to adjust itself just fine when you force it by selecting the superheavyweight paper, but then again you never know. The reason I'm here asking questions is because you people know a heck of a lot more than I do about this stuff. I'll pull the right side cover off the printer and check the part you described.
Thanks. As before, I'm grateful for any input.
10-01-2012 11:20 AM
Sorry to interrupt this thread but do you think, the Z6100 also has such a "switch" or somekind of mechanism to raise or lower the carriage?
10-01-2012 05:33 PM
10-01-2012 11:34 PM
Well, the repair was for a company that sells service contracts. I basically just tossed the ball back onto their side of the court. I told them that I was unable to find a solution after many hours of online research; the service manual does not in any way address the issue; and neither the vendor "experts" they referred me to nor anyone on several online forums knew anything about it. I told them they were either going to have to pay for out-of-warranty tech support from HP, or they were going to have to refer me to some other expert(s) that might know what the issue is. They just told me to close the work order. They proclaimed that, since the end users can print on the HP photo paper by selecting a different (and wrong) heavy paper in the load menu, the issue was resolved as far as they were concerned. The site contact is hopping mad about it, but there's nothing I can do about that. I'm just glad to be shut of the damned thing, though I would like to have found out what was causing the problem. I know I tried pretty blasted hard. For what I'm earning on the work order it probably works out to about eleven bucks an hour, if you consider all the time I spent online looking for a solution.
There are a number of companies that low-ball service contracts like that, then hope that the printer never requires anything beyond replacement of consumables. And then they get nervous when it looks like they might have to spend some real money to fix a real problem. Oh well.
Thanks again to the people who replied to this thread.