Startup Chime but no image, stuck on a white screen.

Hi all,

I just started learning about MacBook logic board repairs but came to a halt pretty quick. I am trying to repair a 12” MacBook that does turn on, I hear the chime, and it makes a sound when I plug in the charger, I don’t have an external monitor to use but the guy I got it from told me it worked on an external monitor. I went looking for bad component to find none. After looking at the display connector, it had some wear on it and I decided to replace it. Successfully done so, but left with the same problem. I also tried all the reset methods found on the internet, for NVRAM, PRAM, safe boot. When I tried using some of the key combinations it looked like the computer would instantly turn of and instantly give the chime again, which I thought was suspicious because normally it would take longer to boot up. Is there someone who could nudge me in the right direction what to look for next. I am not a hero with schematics and board views, but I do know the basic a little.