Dark TV screen on PS2 - anyone help?

[BRONJAY]

I'm using a messiah chipped PS2 on a Sanyo widescreen TV with a Blaze scart connection (blue one with switch between DVD and game). Every game I play works okay with colour but the picture is def dark, as in a lot less brightness on the game setting. When I switch to DVD it appears a lot brighter as it should but the quality is slighty worse graphic wise. I can adjust the TV settings but it affects the TV picture and I really shouldnt have to do that, anyone any ideas?