The Acer Nitro An515-43 laptop powers on and then shuts down

You've already taken some troubleshooting steps, but there are a few more things you can try to identify and resolve the issue with your Acer Nitro AN515-43 laptop:

1. Revert Changes:
   • If you made any hardware changes (e.g., upgrading the screen, changing cables), try reverting those changes to the original configuration. Ensure that the laptop functions properly with its original components before introducing any modifications.
2. Check for Loose Connections:
   • Open up the laptop and check for any loose connections, especially around the areas where you made changes. Ensure that all cables and components are securely and correctly connected.
3. BIOS/UEFI Update:
   • Check if there is a BIOS or UEFI update available for your laptop on the Acer support website. Sometimes, updating the system firmware can address compatibility issues and improve stability.
4. Run with Minimal Hardware:
   • Disconnect external peripherals, including the upgraded screen, and run the laptop with minimal hardware (only essential components connected). This helps eliminate the possibility of a faulty external device causing the issue.
5. Memory Test:
   • Even though you've reset the RAM, consider testing it using a memory diagnostic tool. Some laptops have built-in memory diagnostics that can be accessed during the boot process.
6. Check for Overheating:
   • Overheating issues can cause laptops to shut down abruptly. Ensure that the cooling system (fans and heat sinks) is working correctly. Clean any dust or debris that may be blocking airflow.
7. Check Power Adapter:
   • Ensure that the power adapter is functioning correctly. Sometimes, a faulty power supply can cause erratic behavior. If possible, try using a different, compatible power adapter.
8. Professional Diagnosis:
   • If the issue persists after trying the above steps, it might be beneficial to seek help from a professional technician or the manufacturer's support. They can perform more in-depth diagnostics and repairs if necessary.

Remember, if your laptop is still under warranty, contacting Acer support would be a good idea. They can guide you through the troubleshooting process and provide assistance based on the laptop's specific model and warranty status.