Hello. Recently I purchased a used poco m3 that was dead after an update. It was dead and not charging. After I removed the small shield that was protected the ic chip the device started to charge. Now the battery is at 100%. The problem is that none button combination does not work. I cannot boot the phone. When I plug it on charger shows the logo and the charge symbol and then black screen. When connecting to PC my PC recognizes it as "Linux File-Stor Gadget USB Device". I do not know if it has unlocked boot loader but adb devices shows nothing. Can anyone help? Thanks.