[R-390] VU Meter Issue...newbie on first 390a

[R. David Eagle]

Hello all...Today was my first day of powering up my very first motorola 390a that I have been slowly working on over the last year.  I went through and checked all tubes with my tv7 and found a couple that needed to be replaced.  Today was the day that the speaker finally got hooked up and the rig warmed up.  Much to my surprise, I was copying cw on 40 after a few gleaming moments.
One thing I noticed though, was my VU meter was not working what so ever and I have searched around for common fixes/problems but haven't turned anything up.  Is there any common problems to look for outside of replacing the meter?
Also...I noticed that the carrier meter has a film on the inside of it that is almost brown.  I am somewhat reluctant to pull it apart due to the whole radioactive particle scare, but are these easy to disassemble and clean?


Thanks in advance,
DaveKB8NNU