hmm that kinda sounds like the one my friend gave me today..
he said it didnt turn on at all and so i tried some things:
i plugged it into a charger and the orange led would come on for a second, so it was probably a blown fuse
i bridged fuse2 and now the ds turns on, but only the power led. the green led stays on constantly and is accompanied by a flashing red led.
on the mobo i can see white powder(salts from water?) as well as some rust which tells me that it's probably water damaged
water damaged dses need a new mobo replacement i believe, but that's expensive and you might as well get a new ds/dsi
i hope that's not what happened to your friend's ds...