Yeah, the red, blue, and green CRTs. If you're going to do this yourself, open up the box and see if they are dirty/dusty. They just might need to be cleaned. Also, check the reflective mirror to see if that's dirty/dusty.
BEFORE doing anything, I would register at HomeTheaterSPot and post a question in
this forum. There might be an ISF tech reading that forum with some thoughts, ideas, or suggestions.
I am NOT a repair person and I have NEVER opened a RPTV before. I used to own a Toshiba 57HX81 which is also a CRT-based RPTV. The ONLY reason I got rid of the set is I bought a 65" Mits DLP RPTV so I "upgraded" to a larger sized HDTV. That and the Mits is a HDTV while the Toshiba was a HD monitor (but I digress).
If you have opened up this TV before, it shouldn't be a big deal to open it again. You've checked that the convergence is correct and stuff like that, right?
Peace...