Charging LED is blinking but phone is not booting

Hello

I know about the hardbrick problem in the poco x3 pro phone... but i'm still hoping that it's not the case with my phone.

The problem started with the phone screen suddenly turning white with a blue line (dots) in the middle then the phone shutted down.

Trying to restart the phone failed. After many boot tries, its whether unresponsive or only reach the poco logo then i get straight the same white screen and the phone shut down again.

After a while of trying i can't even boot the phone at all. All i get when i press the power button or when i plug the phone for charging is the LED flashing.

I left the phone without plugging it to the charger for many days straight, i get the same LED blinking but the phone is not booting at all.

I tried charging the phone for nearly 48h straight. again phone is not booting at all. But this time the LED is not blinking when i press the power button. Though after less then half a day being unplugged from the charger, the LED started blinking again when pressing the power button.

So here i am right now hoping you guys have any suggestions or a way to fix the problem.

PS: i took the phone to Xiaomi repair center before. They managed to boot the phone. and the phone worked perfectly fine for about a month before the problem appeared again. What !#^&@! me off is that i couldn't speak to the one who repaired the phone to at least know what is going on. I only managed to speak with the receptionist which was clueless. All she told me is "he fixed it". I couldn't get any more information out of her and i didn't manage to speak to the one who actually tried fixing it. So i'm trying to find a way to fix the phone by myself instead of going each time to the repair center for him to do whatever trick he did and make the phone work for a few weeks.