How can i see/detect what modchip is placed

[guyver3]

I am a newbie on this topic.

Recently i got my PS2 (v7) European version modded with what a Messiah2 Pro.
But i am wondering if it's really the M2 chips since i have some issues:
-using a RGB scart cable i dont get Fullscreen. (its like a widesscreen view, with horizontal black area on top/bottom)

-I get fullscreen using the standard Sony (s-vhs?) cable but with some games (NTSC) theres no color.

-get green screen when watching dvd through this RGB cable.

how can I see or detect if my chip is really a M2? Preferably without opening the ps2, and if i need to, is there somewhere a guide how to open the ps2 in a proper way?
cheers