Doesn't start anymore

I used the phone since 2015 until 2020, then I bought a Redmi just for the sake of upgrading, more apps etc, phone was still working

I recently wanted to reboot it just to have a dumb phone, so I charged it and showed no vital signs. Then I bought a new battery, I started it did a very short vibration, the window logo appeared on the screen for couple seconds, then black; I let it charge but anything changed.

When I plug the charger, still nothing happens, when I try to turn it on it still vibrates for a moment but nothing else happens: no window logo anymore, no anything.

I know I can reset it to factory settings but I would like it to restart it as it was just to keep few of the apps I had (specially an audio recording app and the file manager: lumia OS sucks without a dedicated app for that) and I fear that if I restore the factory settings I will struggle finding that apps still on the store.

Thanks for any advice