I opened the camera back up again, made sure every connector is on right, and put it back together. To my surprise, it worked perfectly. Even the flash. I had shocked myself 3 times while disassembling it. I’ll leave this up as hope for people who made the same mistake.
Update: I’ve discovered that the flickering problem most likely has to do with the LCD inverter - the chip that controls the LCD screen. It is definitely not a software problem because it has the same issue when in the BIOS setup and booting a os from a USB drive. Since the LCD inverter is attached to the screen, I would recommend replacing the LCD screen, not the battery. You can find them on Ebay for as little as $43: https://www.ebay.com/sch/i.html?_from=R4... I think this is a design flaw in this laptop model. I personally would recommend buying a better computer.