Vacuum leakage?

[frankplay]

Hi. Guys:
I have an old PECVD system to set up. Huge leakage in load chamber. Can not pump down under 100 Torr. Rough pump is verified good. I tried alchol and N2. But I could not find obvious leakage. Anyway you can suggest? Thank you.

 

[ddsancho]

I don't know if smoke could contaminate your system, but sometimes I test with incense to find out vacuum leakage.