Anbernic RG40XXV - haven't used it in a while. Plugged it in to charge. Screen "lights up" Yellow LED and Green LED comes on

Still can't get the device to turn on after letting it charge a few hours. I'm not sure why the screen would sort of "come alive" when plugged into the charger. The Yellow LED that indicates charging lights up as well as the green LED next to it.

If I hold down the power button while it's plugged in, the screen will go "dark" and the Green LED will turn off.

It's been a while since I've used / messed with this.

Am I doing something wrong or, is the device "dead"?