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DuncanDee
Posts: 1
Member Since: ‎04-20-2010
Message 1 of 9 (8,211 Views)

L7780 Printer - Potential Printhead Problem

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?

 

Kind Regards

 

Duncan

Student
NigelH
Posts: 1
Member Since: ‎10-14-2010
Message 2 of 9 (7,699 Views)

Re: L7780 Printer - Potential Printhead Problem

Duncan

 

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.

 

Nigel H

Intern
Hui_Assist
Posts: 45
Member Since: ‎07-30-2010
Message 3 of 9 (7,682 Views)

Re: L7780 Printer - Potential Printhead Problem

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?

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Honor Student
YveIEBE
Posts: 4
Member Since: ‎10-26-2010
Message 4 of 9 (7,616 Views)

Re: L7780 Printer - Potential Printhead Problem

Printhead may need replacing.

Student
ucbkid
Posts: 1
Member Since: ‎12-03-2010
Message 5 of 9 (7,460 Views)

Re: L7780 Printer - Potential Printhead Problem

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??

Honor Student
kevina7
Posts: 2
Member Since: ‎12-03-2010
Message 6 of 9 (7,454 Views)

Re: L7780 Printer - Potential Printhead Problem

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!

Honor Student
mlaross
Posts: 2
Member Since: ‎06-24-2009
Message 7 of 9 (6,615 Views)

Re: L7780 Printer - Potential Printhead Problem

[ Edited ]

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.

Student
hdbrad
Posts: 1
Member Since: ‎08-21-2011
Message 8 of 9 (5,867 Views)

Re: L7780 Printer - Potential Printhead Problem

[ Edited ]

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

Student
HPForm4Me
Posts: 1
Member Since: ‎03-09-2013
Message 9 of 9 (2,478 Views)

Re: L7780 Printer - Potential Printhead Problem

[ Edited ]

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!

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