Hardware Switch not charging after disassembly

[Whitesttax]

After I disassembled my Switch to fix a loud fan first I turned on the console but there was no image, I doubled checked and the LCD cable wasn't connected properly, then when I tried turning it back on it would not, and not appear the charging icon either when connecting to power. So I got my sister's Switch and used the motherboard on this Switch, with the same LCD and Battery.
Connected only the 2 LCD cables + Battery connector and the charging icon showed up... So because I can't turn on or charge with the other motherboard I'm thinking something to do with the battery connector? As the battery is working, should be related right?
I spent a whole day on this already and I have no idea how to fix, I'd appreciate any tips.

 

[jkyoho]

CHECK IF YOU LCD CONNECTOR has missing pin/legs like this.

 

[Whitesttax]

@jkyoho Can't post photos cause I'm a new member but the thing is, if it was a problem with the LCD it would turn on and make sound when I used the joy con like the first time when I had the LCD disconnected, right? I'm worried I might have fried the motherboard.