Ink system failure

[AnalogueMan]

After three years of almost flawless use, my HP7610 suddenly came with this failure:

"Ink system failure", power off the printer and restart it. But that did not help.

Some internet browsing showed advices of HP like replace ink cardridges due to possible leakage, which I did

but without result.

And this only after 3 years after purchase!!

So there must be some kind of "service mode" to enter (standard for instance for every Television) and then

performing some kind of reset to get things working again.

What is the key combination to do this?

[AnalogueMan]

Why is there nobody from the HP support responding on my problem?? Is it not severe enough??

I am ver, very disappionted