HP L 1500 - Does anyone know which valve part number this is ?

HP L 1500 - Does anyone know which valve part number this is ?

I have the following problem, The light cyan came up with an error saying intermediate cartridge problem, this was replaced, the cartridge still did not work, I have replaced the PIP also. then the flashing lights at the cartridge stopped working so I have replaced the cartridge connector, the lights are working again but the machine is registering any new cartridge as empty even a brand new full one. the same cartridges work on my other machine. any suggestions?

Thanks