Epson P800 not printing Yellow

[Jezdo 0]

Just installed Chipless f/w on my Epson SC-P807 after not using it for almost a year.

I tested the printhead, every colors printed perfectly except yellow. There is no yellow at all.

I cleaned the printhead a few times but it's still the same.

Then I checked the ink cartridge, the yellow tank is still full. The printer didn't draw yellow ink at all.
The ink line looks good, full of ink, no bubbles at all.

So I installed the original yellow tank to check if the refillable tank is faulty, but it's the same, completely no yellow.

I never faced this problem before.
Do you have any suggestion?

 

[Cryptikz 0]

Contact Epson service for warranty in this case.