Is this i960 printhead toast?

[Boomhauer]

Ok I have read most of the tales of clogged PH's on this forum including Granddad's which involved a blockage in the body itself.

Firstly the problem:

Running a nozzle check all colors look uniform except the PM which shows a rectangle only half filled in; that is, the top half of the rectangle looks acceptable with the bottom half very pale. The difference between the top and bottom halves is sharply defined. Also under letter 'E' instead of a uniform color swatch I get vertical lines the color of PM with white space between those lines.

Does it show up in prints? Yes I have seen banding.

What I have already done:

Alignment check. There is zero difference in the 'E' pattern obtained regardless of setting (+7 to -3).

Replaced PM cartridge. No help.

Removed PH and soaked overnight in a 50% ammonia solution. No help.

Is this a clogged PH which requires heroic declogging attempts, a body clog, an electrical problem or what?

I am ALL ears.

 

[Boomhauer]

Any help appreciated - thanks!

 

[drb_52]

Boomhauer, I have the same problem with my i960 except mine is with the magenta. Sorry to see you didn't get a response, as I'm pretty sure it would have helped me too. Have you solved the problem? I did the same trouble shooting you did and got the same results. I bought the i9900. I plan to do some experimenting with the i960. I'll let you know if I manage to get the PH working properly.

 

[mikling]

I suspect that the heater of the problem color in the printhead is the problem and not the nozzle on the exterior. If you ran the printhead while the cartridge was not supplying ink properly, it could lead to this.
Well first, it sounds like a weak jet because you've already soaked the printhead and cleaned the exterior nozzles. What can cause a weak jet? It could be electrical, yes. But the likely cause is probably caking on the heaters when ink bakes over the heaters that are supposed to instantly boil the ink. If the heaters get coated, it insulates it and it won't boil as violently thus a weaker jet. Be aware that this is a potential death spiral of a printhead if you're not careful by rectifying the problem which is normally just a bad supply of ink by cart or whatever.
Try soaking again but this time using warm running water, angle the water at about 45 degrees to the printhead to try and penetrate the nozzles and get some flow into the chamber going. Try different angles from different directions. Do this until no colors are apparent. Now turn the head over and set the tap so it runs at a column width about the size of the inkport. Put the problem color uder this column and hold it there. We are trying to force warm water through the problem color passages to clear any buildup or caking. Hopefully we will be able to disoolve the caked ink around the heaters. Continue until there is no color from the printhead. Turn over and repeat.
Now soak and repeat.
Before putting the PH back in, make sure that the area behind the contact board is dry or you'll get a defective printhead flash and freak out.
Good luck. Works many times and be careful of "clogs" which rarely happens with frequently used printers. The printer manufacturer saw to that with multiple clean operations on start and stop and in between. Caking though is much more prevalent on frequently used printers because of the not perfect condition of the cartridges.

 

[drb_52]

Thanks mikling, I'll give it a try an let you know how it turns out.