Powers on then off

Hello. So a dad here. I replaced my son's dsi xl lower screen and it worked perfectly. He went to use it one day and he brought it to me saying it wouldn't power on. So I look at it and it powers on then off. So dig into it after reading the other post about this issue. What I came across is that if I unplug the right hand bumper button it boots up just fine. So I got a different rh bumper and same problem. So I need help 😕 Thanks in advance for any information. My son is not like other kids. He loves his old-school gaming consoles more then the new ones. My next step would be to source a new main board.