most pal TV's have support for ntsc built in (i.e they will play either or!) but this doesn't mean all do. Depends on how old yr tv is. Some older tv's give sum strange effects! Also as u can't open up yr ps2 u cant tell whether the screen fix link is fitted (as mentioned earlier). Sounds like it ain't. Also lead are you using to play yr games..........RF Lead, Composite scart lead or component (RGB) scart lead? All these make a difference. Also if u using a RGB scart lead into scart socket 2 of yr TV the chances are that it is working in composite mode as usually on TV's only scart 1 supports RGB input.
Hope this helps
Best bet....Forget the guarentee and fit or get fitted a matrix infinity.....THE ULTIMATE CHIP!!!!!!