asked Jul 10, 2011 at 1:26pm
Hp HP DeskJet 600

HP Officejet L7780: Cyan printhead keeps failing

I have an HP Officejet Pro L7780 and the Cyan/Magenta printhead keeps failing (more often the cyan I think), I barely get 10 000 prints per head for the last 4-5 heads when they normally last 50 000 prints.

At 3 printheads I said maybe it;s just really bad luck with the printheads, but now it's 4-5 cyan/magenta heads that failed very prematurely so it can't be bad luck with the heads.

I'm trying as much as possible to keep this printer alive as the new ones use pigment ink which is hard to find quality pigment ink and cheap pigment ink instantly breaks the $600 machine (I've had it happen, that's why I'm avoiding the new ones like the plague).

What could be causing my printheads to keep failing? Interestingly it always seems to fail with the outer nozzles dying slowly inwards, as if it's drying out from both ends, could it be the sealing cap that's no longer airtight? Is that hard to replace and it is the same as in the HP Officejet Pro K550? I have one of those I use for parts to repair my L7780 to keep it alive as long as possible, it's at 1/4 million pages printed and still working great other than the failing cyan printhead.

Sounds like you really work this printer. Depending on what you print, ink usage can go up fast. Always check the dates! Expired carts are plentiful out there, so dont trust a salesman.
It always seems to be the K\%Y cart that goes on printers I work on. A thought, is it plugged into the wall directly, or a strip or UPS? Getting that many prints all the time out a cart is doubtful. They just dont fill them up anymore. What a racket!
by unknown on Jul 12, 2011 at 9:43am Add comment
I don't buy cartridges, my printer is connected to 1 liter bottles of each color with make about 50 000 prints each for $50.

With the print head problems, the printer has sat unused for 6 months, and the cyan I already had since a long time.

Is it possible it's my cyan ink that's gone bad? If it was bad could I really do 5000-10000 prints before the print head starts failing?

That does make sense though, as a non airtight seal would also affect the magenta which is on the same print head. Perhaps there's nothing wrong with the printer at all and it's just my cyan ink?

I guess it's worth buying new cyan and flushing out the printer tubes before committing to the new models that use hard to find pigment ink (I would never buy cartridges).

Oh, and of course cyan is the color I have the most of left (about 900 of 1000 ml), it couldn't have been one of the nearly empty bottles? I'll still keep the cyan ink in case that's not the problem.
by unknown on Jul 13, 2011 at 1:23am Add comment
So I was getting a printhead error - so i purchased a new printhead - put it in and the printer is still giving me the message that the NEW printhead is damaged or missing :(
anything else I can try???

by unknown on Oct 20, 2014 at 7:49pm Add comment
Take the printhead out and clean the contacts in the printer. Use a cotton swab moistened with window cleaner. - moe