Why is my lenovo miit520-IKB 2-in-1 Tablet not booting up

good day, my name is Anthony and i have a lenovo miix 520-IKB 2-in-1 Tablet, this lenovo was sent to me by my brother from the UK last year November 2024, and after using it for about two months, one morning i woke up and find and turn on my laptop and its refuses to boot up, i try everything i could but was not successful, so i told my brother to help me with a motherboard to change if is possible , and he did and after changing the motherboard, i noticed the laptop only shows a battery filled sign at the middle of the laptop and immediately after 10 seconds its goes off, so please what can i do rectify the lenovo miix 520-IKB 2-in-1 Tablet