we have a blocked nebulizer Gas Passage on ou MP-AES. N2 generator working fine

We have a guide for cleaning the nebulizer.

https://www.agilent.com/cs/library/technicaloverviews/public/5991-9034EN_ICPOESblock_techoverview.pdf

Its also worth verifying the gas is making it to the nebulizer. You can do this by taking the gas tubing off the nebulizer and manually turning nebulizer gas on through the instrument panel. Feel to make sure you can feel flow.