My daughter's Nintendo DS lights up for a split second then dies when it is switched on, battery voltage tested OK.

There is a possibility that your battery has developed a short circuit or is so bad that it pulls down the charge voltage on the charger. You are therefore left starved of a power and therefore no function.
If possible, disconnect the battery and run the DS on the charger power alone. If the DS starts to work, I suggest replacing the battery.

Possibly a bad charger? Try getting a new one.

Check L2 near the power switch on your DS mobo. That part usually get loosen or taken out when you drop your DS. And usually you can recover it when dismantling your DS.

It may need a new Battery or the inside may still be wet. Try the battery first-- ya can get them online and while you wait on the battery let the DS continue to dry out

It just means you are low battery. Have you tried recharging it? Just turn it off and on and should you should be ok.

Hey if you have a warranty nintendo might repair or raplace the Ds.I thought about replacing the charger or place the charger in another power outlet.I hope I helped.

I would contact nintendo if you have a warranty. Also try changing the battery or charger on the internet

for ur sons DS try to move it around to find a signal. for ur daughter's, trying doing the same first and if it doesnt work, buy a new charger if the new one doesnt work its the DS

You may need a replacement battery. Check ebay for replacement DS batteries.

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.