Nintendo ds lite not powering up?

Hi
I have a ds lite which doesnt powr up, this is what happens when i try

The green light comes on, after 1 second the light becomes brighter, after one more second the bottom screen flashes on / off, as it goes off then the green light also goes out, thats it.

It is possible that some water has been spilled on the unit, inside the battery compartment there is a little small square which i assume is a water detector, this is white with pink spots, on the base of the motherboard is another one which is completely pink.

There seem to be a lot of ds out there on ebay so i'm hoping that the probable cures are known somewhere, failing that does anyone know how to trouble shoot these things, as i see it the only possibilities are the motherboard or the screens.

By the way i have tested the F1 and F2 fuses which are both ok.

Thanks for any info available

Paul