Ds lite sleep mode

SOURCE: nintendo ds lite

It's not likely to be battery, but fracture in ribbon cable to top screen causing this. Both screens must be connected or you get the symptom you've explained.

SOURCE: NINTENDO DS LITE WON'T CHARGE OR POWER ON

Hey everyone, not sure if this will work for everyone, but its worth a shot.  my problem was identical to all the others here, a flash of orange and then nothing.  
i thought perhaps those little metal contacts on the battery and the ds had build up a little corrosion, interrupting the charge.  so, i took some rubbing alcohol and q-tips and gently scrubbed them clean, both on the battery AND the ds side.
After this, my ds has worked flawlessly.  Hope it's the same for you!

SOURCE: Nintendo DS Lite Flickering screen

hey i think i got a solution, read the link i gave below credits to votahuan, its for adjusting screen flickers in both top and lower screen of ndsl, however i need you to do me a favor in return, hope you do not mind posting up the pics for me at [email protected] once you found the two hidden screw at ndsl, im just having hard time finding it in fat nds, so i need a rough i dea of where it mite be located. Heere's the link anyways :-

LCD FLICKER SOLUTION

SOURCE: when plugging power to the DS lite the led flashes orange once

I think if the orange light flashes once it means it has a full charge.

SOURCE: NINTENDO DS LITE WON'T CHARGE OR POWER ON

you have to buy a new battery