[lcaillo]

I am not specifically familiar with that set, but I suspect that it was made by Philips and you are experiencing the contaminated coolant in the blue CRT that is very common with Philips CRT RPTVs. The green will do the same thing. The CRTs will have to be taken apart, cleaned thoroughly, re-assembled, new coolant installed, and the set will need to be focused, converged, and gray scale will need to be adjusted.

As far as I know, Marantz never had a DLP set in a RPTV design.

Because this is a common problem, I will be starting a thread with details about the problem and how to resolve it. Look for it over the next few days if you plan to DIY. If you will have it done by a tech, stay away from anyone who says that they change the coolant without taking the tubes out and without disassembly. This is not the proper way to solve this problem and is dangerous. Any drips or leaks that get onto a circuit board, the high voltage leads, or the yokes can be catastrophic.