i550 missing alternate lines...

[embguy]

I got an i550 from the local recycle group today. It prints only on alternate lines. Nozzle check shows missing black grid pattern at the top and bottom. It prints only the middle section of the black grid. The color grids are are perfect.

- After a few deep cleaning cycle, it does the same.
- I saturated the purge pads with cleaning solution. It disappears after I did a purge. Therefore, the purge system is working.
- Used an eraser to clean the electrical contacts on the print head. This did not help.

I put Windex on the purge pads and let it soaks over night with the cleaning cartridges. Hope this will remove the clog.

At the mean time, I like to use a good print head to test this printer. A few people in this forum reported that "dead print head kills printer". Is there any danger that problem printer will kill print head?

 

[ghwellsjr]

It would be helpful to upload an image of your nozzle check.

We need to see if the missing grid lines follow a pattern that would indicate an electrical problem.

 

[embguy]

The top nozzle check is from the bad i550.
The bottom nozzle check is from one of my good i550.

After I have a chance to compare a good nozzle check, my original comments was wrong. The bottom half of the black grid is missing. The top half is not complete. Some columns are missing horizontal lines at the top section. All vertical lines are missing at the bottom section. Only a few horizontal lines are printed at the lower half.

 

[ghwellsjr]

This is not an electrical problem. There is no danger of putting this print head in another printer or putting another printhead in this printer.

It is a classic nozzle clog problem and can probably be fixed with repeated cleanings using Windex. See some of my other recent posts for details on how to do this.

 

[embguy]

This is not an electrical problem. There is no danger of putting this print head in another printer or putting another printhead in this printer.

It is a classic nozzle clog problem and can probably be fixed with repeated cleanings using Windex. See some of my other recent posts for details on how to do this.

Thank you for your input. I will keep trying to unclog this print head.
What are you looking for to determine whether it is a clog or an electrical problem? Thanks

 

[ghwellsjr]

For an electrical problem, we are looking for consistent regular pattern such as no grid segments on one half of the pattern. It could be the top, left, right, bottom, every other grid segment, etc. When you said that the bottom half is missing, it wasn't completely missing, there were seven or eight segments present. That's why I wanted to see an image.

Random missing segments in an area that is largely present or random printing segments in an area that is largely absent are typical of severe clogging. But I have received printers from eBay where none of the segments printed for any color and was able to unclog them all. You'd be surprised how doing just one cleaning and letting the printer sit overnight can unclog a lot of nozzles. I don't recommend removing the printhead from the printer to unclog the nozzles. I have ruined to printheads this way. Let the printer do its job. It was designed to unclog nozzles. It's just that a little Windex can speed up the process.

 

[embguy]

I think I may have screwed up the print head.

I cleaned an empty black cartridge and fill it with Windex. Did quite a few deep cleaning cycles. I was able to get 50% of the lower half unclogged. I did more Windex cleaning cycles. Then, still using Windex cartridge, I started printing a page with 1" black column between deep cycle. At the beginning, it showed improvement. Suddenly, the lower half of black grid pattern disappeared - not even a single trace. The print head may be damaged at this point.