It is possible the battery has become completely flat. Sometimes if you buy consoles such as this online, it can be quite common for the battery to not be included!
If I am missing anything or if there are any items you think I should add to this guide, please feel free to let me know in the comments below. So, I am starting this new How to Fix It series of posts to share with you what I have / am learning as I take apart old games consoles to repair them. As a result, I’ve learned a great deal about troubleshooting various issues with this console. Over the last number of months I have disassembled a large number of Nintendo DS Lite consoles. Nintendo DS Lite – How to fix it Introduction