Partially booting iPad

I have an iPad a1219, inherited from my brother, which never reaches the Apple logo screen. Instead, its dark greyish screen flashes back to black and it tries again. This repeats interminably. It’s possible that it was originally the power, since it had sat uncharged for ages. But it’s been plugged in likewise for a very long time. I can only assume its battery is now fully charged, since the screen never shows anything more than a bit of brightness.

So: any recommendations from the experts on early iPads?

Thanks to all!

Alastair Milne