Snes video has green tint

[macewind]

Ive been trying to find a solution to this for ages and wondering if anyone here has came across is before?
My snes works fine but the colour is tinted green, not green bars, its as if one of the colour channels has completely turned off.
Ive got a second snes that displays the game perfectly so I know its not the cables or the cart itself.
I've tried adjusting the crystal by turning the screw but have seen no change at all in the colours.
Ive cleaned the pin connectors, no effect.
Ive checked for broken lines on the board itself but can't see anything wrong. I'm at a loss!
*edit* I've tried using both the rf and the red white and yellow av cables but its green on both types

[Niku-Sama]

looks like you've lost your blue color channel.

what board revision is this SNES?

[macewind]

i'm not sure, where would i find that out? Also where would the blue channel be on the board?

[Niku-Sama]

its under the Nintendo logo on the top right of that board you posted a pic of.
looks to me like it says SP-CPU-01

seems to me that this might be a European system. are you in an area using a PAL tv system or are you using a euro snes on a US/JAP tv?

it also looks like theres some damage to the board behind the connectors too

did you take the heatsink off before taking the pic?

[macewind]

Yeah its a pal system and im in the UK so everything else is pal too.
I did remove the heatsink yes, and i've also sanded down the board slightly as it was black. I was worried corrosion had eaten away the traces but once I got down to copper everything was intact.

[Niku-Sama]

well I am at a loss on this one as I cant find any thing that suggests this problem, plus the layout of the board isn't something I am quite used to.
my guess is the video encoder either has a weak connection on the blue output pin or the blue output decided to go out on it all together.

you said you checked for broken lines but its obvious blue isn't getting to where it needs to be, almost as if its before the conversion to A/V and RF outputs. could be a cap, could be a broken solder joint or the blue on that chip is toasted too.

the only way I can think of checking it would be either to replace the encoder chip.

its possible that the little chip that's parallel to the cart connector might be the encoder chip for it, only way to tell would be to do the component mod as long as that's an encoder chip like the S-ENC or BA6594AF but odds are, being a European system, its different. it'd be a lot of work but that's the direction you'd have to go to narrow it down