Hey there, let's break down the potential hardware issues and fixes for your Acer Nitro 5 AN515-44 screen flickering problem—since you’ve already confirmed it happens in BIOS/boot and ruled out GPU overheating, we can narrow down to these common culprits:

• Loose or damaged screen cable
  This is one of the most frequent causes of laptop screen flickering, especially since you noticed some areas aren’t affected. Regular opening/closing of the lid can wear out or loosen the cable, leading to partial contact issues.
  Troubleshooting/fix: Try gently opening and closing the lid to see if the flickering changes (if it does, this is a strong indicator). If you’re comfortable with basic disassembly, power off the laptop, remove the battery, and check if the screen cable is securely plugged into both the screen and motherboard. If re-seating it doesn’t work, you’ll need to replace the cable with a compatible one for your AN515-44 model.

• Faulty screen panel
  The fact that only parts of the screen flicker suggests a localized issue with the screen’s internal driver circuits or pixel modules, which has worsened over time.
  Troubleshooting/fix: Connect an external monitor to your laptop. If the external display works perfectly without any flickering, this confirms the problem is with your laptop’s built-in screen. In this case, you’ll need to replace the screen panel—reach out to Acer’s official service center or a trusted repair shop for a compatible replacement.

• Malfunctioning motherboard display interface
  While less common, the motherboard’s connector for the screen cable could have oxidized pins or loose connections, causing partial signal loss.
  Troubleshooting/fix: If you’ve checked the cable and screen, power off and disassemble the laptop to inspect the motherboard’s screen connector. Look for bent or oxidized pins—you can gently clean oxidized pins with a rubber eraser (make sure the laptop is completely powered down and disconnected from power). If the connector itself is damaged, repairing or replacing the motherboard would be the next step, though this is a more costly option, so prioritize checking the cable and screen first.

A quick note: If your laptop is still under warranty, avoid disassembling it yourself—contact Acer’s official support directly to get it repaired covered. If it’s out of warranty, start with the cable check since it’s the easiest and cheapest fix to try.

备注：内容来源于stack exchange，提问作者Anonymous