The HP Community is here for you.
04-20-2010 09:28 AM
I'm using a HP Officejet L7780 Printer - when printing a document such as a letter some lines of black text appear to be missing the very top row of print - ie every tall letter like "t" is mising its top whereas small letters like "e" appear normal
This problem does not occur on every line of text maybe one or two lines per A4 page
I have done a Print Quality Diagnostic Report which says my Printhead health KY and MC are good
Test 1 says lines should be straight and connected - which they are not so i pressed Realign
Test 2 says thin white lines on the color blocks means i should clean the print heads - lines appear on the black block so i pressed Clean Printheads
Test 3 says to check if white gaps appear next to arrows - they do so i pressed to calibrate linefeed
I have now completed all 3 Print Quality tests and the associated actions - so i ran the Quality Diagnostic Report again with same results
I therefore repeated the "cures" and ran tests again - still no improvement
This only started hapening a week ago - i have had the machine over a year and had no problems till now
has anyone any helpful hints?
10-14-2010 04:26 AM
Have you resolved your problem as I have just experienced the same sort of thing. Over the past 2 days, I have tried everything from cleaning the contacts to changing cartridges with no improvement. Every time it prints a test page it says "alignment cancelled - refer to documentation"
Any help would be great.
10-15-2010 03:35 PM
Hi, Sounds like you are experiencing print quality problem with black.
For the clean printhead procedures, did you go through all the steps? I remember there will be a diagnostic page printed out after each cleaning printhead step and if the print quality is still bad, you could click continue or OK to proceed with more extreme servicing.
Before you have this problem, did you have the printer idle or stored somewhere for a long period of time? Or is there a power shutdown which cause printhead to be not capped?
While I am an HP employee, I am not a expert on all our products. If I offer advice, I'm not speaking for HP on how to solve an issue, but I'll do my personal best to help you.Was your question answered? Mark it as an Accepted Solution! See a great post? Give it a Kudos!
12-03-2010 10:23 PM
I have a similar problem. Mine started when I observed thin black lines on 4x6 in photos spaced 7/8 in apart. After calibration- I have the same problem. I see it in test pattern 3 on the print quality page. The support tech was very helpful but HP as a company is no help so far.. Checkpoint Monday Dec 6. Tech Mgt will call me.. Anyone else see an issue in their photos??
12-03-2010 11:16 PM
I had a similar issue, but my problem was with the black ink. It would not print ANY black ink at all. Every time I tried to print, it would go through an alignment process, ending in failure. After trying everything imaginable, and with nothing else to lose, I finally took the black/yellow print head out and wiped the print nozzles with a paper towel to see how well the ink was flowing. The yellow was fine, but the black ink seemed dry. So.....
I took the print head and layed it in a bowl with about 1/2" of warm water, black side down and submerged. I let it soak for about 20 minutes, until the black ink started seeping out of the full length of the print nozzles. I took it out and dried it off with a paper towel, and now when I wiped the nozzles, the black ink was flowing nicely!
I put the print head back into the printer, and bingo, it flew right through the alignment process and is printing wonderfully!
Hope this works for you.
P.S. Since my only option left was to go and buy a new print head, I didn't feel that I had much to lose if I ruined the current one. As it turns out, I saved myself $75!
04-15-2011 04:16 AM - edited 04-15-2011 05:11 AM
If your L7780 is still under warranty, contact support and the black/yellow printhead should be replaced at no costs to you. However, you will have to purchase a new black/yellow printhead if the L7780 is not under warranty.
Yet, if you have contacted support re the print quality problem [even if your L7780 were out of warranty] you should--still--be able to get the printhead replaced gratis because there is a history (Cases/Tickets).
And, in the alternative, contact Executive Customer Relations if the history of the problem fails to get the printhead replaced.
... Good Luck.
08-21-2011 01:08 PM - edited 08-21-2011 01:11 PM
I did the same thing...remove the print head. fill a bowl with 1/2 of hot tap water, submerse the black side in the water, wait a few minutes..or until the black is bleading into the water. Paper towel dry......worked great. like new
03-09-2013 09:35 AM - edited 03-09-2013 09:41 AM
I also did the same thing...removed the print head. (You can get the printhead carriage to slide to the left to allow access by pressing the OK but for 5 seconds, if it doesn't do it automatically when you open the top cover). I removed the black/yellow printhead since it was my black that was printing with horizontal lines everywhere. I used an empty/clean whip cream container (or any shallow bowl) with about 1/2" of hot tap water and submersed the printhead for a couple minutes and dabbed it dry with a paper towel. It worked great!...like new again.
P.S. The only thing I wasn't perfectly clear about was what part or how much of the printhead to submerse. To further clarify, using the exact orientation of how the printhead sits in the printer I consider it having a top (the part you see before pulling it out), the bottom (opposite side), the front (part closest to me), the rear (opposite side of front) and then you have the left and right side. Upon removing the printhead, it was obvious to me that the bottom of the printhead (output) was covered (caked) in black ink. At the front of the printhead is the nipple or needle shaped point (input) that pulls the ink into the printhead. It looked slightly gunked-up. By laying my printhead down on the left side in about a 1/4-1/2" of water it was deep enough to submerse the entire half of the printhead which includes both the black input and output areas at the same time. Maybe it is ok to soak then entire printhead, but I didn't want to risk it since the Yellow side (right side) of mine had no problems.
P.S.S. After re-installing the printhead and closing the top cover, the automatic alignment process took longer than I thought. It lasted nearly 10 minutes, but I just let it run its course and eventually it stopped on its own and then printed 2 confirmation sheets and then said it was successfully aligned!