phone vibrated twice, now won’t turn on

I’m trying to fix a red iPhone 11. I was offered it (broken) so I thought i’d wing it and try to fix it.The phone vibrated twice then became unresponsive.

Here’s a time line

I replaced the front and black glass. I managed to replace it but in turn, I broke the wireless charging, the flash module fell out and the camera gets blurry.

Next i tried to fix those previous problems. I bought new flash and took another look at the camera.

I worked on the phone, disconnecting the sim card, cameras, battery, and screen ribbon cables in hopes of replacing the flash. Unfortunately when I managed to turn it on the screen was unresponsive to touch.

I try again,uninstalling/reinstalling the necessary pieces, then the phone looped the apple booting screen.

Finally, I unplugged/replugged previously stated cables again but i forgot to unplug the battery. The screen was once again unresponsive. I repeated the process again (forgetting the battery again) but this time the phone vibrated twice as i’m reconnecting the cables. Now the phone is completely unresponsive.

Am I right to assume it’s a battery issues or a logic board issue?