HP DJ 5500 - Error 5515 Replace repeatedly appears error, printhead

icvasilescu

Hi, I am starting here on oasq.com with a issue about my HP DesignJet 5500 42". The problem is that LightCyan printhead fails too often. So I lose the lightcyan printheads after only 200 or 300 ml. The error displayed is "5515 Replace"
This had happened many times in the last period in situations like the following:
1. the printhead fails during printing and the printer stops and give an alert that the head has failed.
2. the printhead fails during printing and the printing continues and the lightcyan color does not appear on the print from that point on.
3. after a contact cleaning when put back in its slot the replace error appears.

After this error appears I turn the printer off (from the button in the back) and let it like this for a day or two. When I turn it on again:
1. sometimes the error disappears and I can print again for a while. But after 2 or 3 prints of 2-3 meters long, the error reapers and remains like this. Sometimes this comeback can happen even if I turn the printer on immediately, and not waiting for a day to pass.
2. othertimes the error is final and remains even after couple days.

This is happening only with LightCyan printhead.
The contacts are always clean.
Sometimes it stars with 0515 Replace error.

What could be the problem as I can't figure it out and what can I do?