Nebulizer Problems

Hello everyone, I am new to this group and teach science & engineering at a vocational school in Germany - our students are trained to become cert. lab assistants. We (still) operate two old Aanalyst 300 units - given to us by labs that replaced these models long ago. Because of virtually no funding (for replacement or repair), we have to work with these and make them run as long as possible. In one unit, the nebulizer is not working: Gas bubbles into the sample container at a very high rate. I have taken the nebulizer unit apart, cleaned it thoroughly(both with the correct cleaning wire and ultrasonically), greased/replace all gaskets, replaced the capillary tube... maybe someone has another idea on how to tackle this. Thank you!

Equipment: PerkinElmer - AAnalyst 300