10-19-2011 11:18 AM - edited 10-20-2011 10:34 AM
This printer has about 9200 prints through it.
All of a sudden it started dog earing the RHS LE (leading edge - obviously) of 90% of the paper feeds.
I suspected this was related to the mysterious actuated thin, vertical black finger that is at the very end of the paper tray.
I was able to determine that this was where the damage was occurring by starting a print and then as soon as the paper started to feed, pull the power cord. I was able to stop a sheet after about 1" of feed and could see the dog ear in its infancy.
At this stage of feed, the paper is at least an inch before it engages the 4 rear rubber rollers.
The LE is about even with the tops of the row of black plastic guides that are "behind" the ABF (actuated black finger).
I know this is a printer about which little is known on the internet. The feed mechanism and internals in general are nothing like earlier, cheaper, Photosmart printers. (I wonder if this printer is actually manufactured by HP???)
Since the dog ear is at the ABF, I suspect it is broken or malfunctioning.
I also admit that although I could see nothing wrong with the paper tray, it could be a tray issue.
I am sure this is a known failure mode, however, getting someone to shed some light on it is another matter.
10-20-2011 10:28 AM - edited 10-20-2011 12:55 PM
Today, I realized I could actually run the printer with the rear panel removed.
That provided a clear view of where the dog earing was occurring.
Now I can see, page after page getting eared right before my very eyes.
The LE of the paper is getting stuck at the bottom of the AFB (Actuated Black Finger.) The LE is not sliding up the AFB.
NOTE: I just looked at a C5550 and it has the same style back panel and 4 rear rubber rollers, however, the AFB has been completely redesigned. Now it looks like an the actuated "tabs" in the Photosmarts that have the "Big 2" Rollers" in the rear. It is interesting that the B2R printers have a pair of these tabs, a LH and RH one symmetrically located, while the D7260 and the C5550 have only the RH and not the LH.
In the first pic, you can see the LE with about a 1/8" long dent right by the 2nd roller. Again, at this 2nd location, the LE is getting stuck and not sliding upward into the paper path. (With this new knowledge, an endoscopic inspection might reveal something, but I'm not that keen on packing up the endo "kit" and moving it to office - nor printer to home. Yet, that is. Eventually, Curiosity killed the cat.)
I have pics of the feed interrupted at the jam point and also a movie of the jams showing their formation.
I am going to try to change the thread title to include PHOTOS, if I can't, I'll start a new thread with PHOTOS in the title.
Since I also have a Video, I'm not sure what I have to do to include that. It is a 50MB AVI file.
10-21-2011 02:20 PM
Perhaps some insight into the paper feed mechanism.
I have looked at an Officejet and Deskjet printer, and the LE of the paper is simply shoved into the paper path.
There are no actuated fingers, either symmetric or one-sided.
So why to the Photosmart printers appear to have these actuated "gate keepers?"
I propose the answer: Photo grade paper tends to stick together and these fingers are a mechanism which separates the sheets.
If this part of the paper path was easily accessible in the D7260, I would consider doing a "tabectomy" like a good sinus surgeon hot after polyps.
Further inspection, shows via a dental mirror, that the LE actually rests under the actuated black finger, ABF.
In this case, if the ABF does not retract in time or enough, the corner of the paper will be dog eared.
That means either the timing of the ABF is off, or the positioning of the paper relative to the ABF is off.
EXPERIMENT: Since a single sheet is clearly seen to sit under the ABF, what if a full paper load was placed in the printer. That way the LE of the top sheet would be well up the ABF.
Unfortunately, the dog ears continued.
CONCLUSION: Something must have failed in the actuation fo the ABF. Either in time or position. This is a fairly esoteric failure but I'm sure one that has been documented and solved. Unfortunately, those people are not talking.
What do you think, Bob?
Thanks in advance,
01-21-2012 09:42 PM
CAUSE: Malfunction of Service Station Carriage - it would not nest properly due to ink building and possibly the squeegee rubber coming loose and laying in the carriage.
REASON FOR JAM: The articulating black finger is driven by the service station carriage. If the carriage cannot nest properly when the head undocks, the finger does not articulate out of the way.
REPAIR: Just clean everything out with hot water. However, printer must be disassembled completely down to the bare sheet metal chassis!!! It is not that bad a job if you know how to do it - which I do now. (I'm probably the only person in the world that has done this repair.)