Detecting a bad laptop motherboard can be challenging, but here are a few steps you can take to diagnose potential issues

1. Power issues: Check if the laptop is not turning on at all or if it is randomly shutting down. This could be an indication of a faulty motherboard.

2. No display: If the laptop powers on but there is no display on the screen, it could be a sign of a motherboard problem.

3. Beep codes: Listen for any beep codes during startup. Different beep patterns can indicate specific hardware issues, including problems with the motherboard.

4. Overheating: If the laptop overheats frequently, it may be a result of a faulty motherboard.

5. USB or port issues: Test the USB ports and other connectivity ports. If they are not working or are unreliable, it could be a sign of a motherboard problem.

6. Random restarts or crashes: If the laptop restarts or crashes unexpectedly without any apparent reason, it could be due to a faulty motherboard.

7. BIOS errors: If you encounter errors or warnings during the BIOS startup process, it could be an indication of a motherboard issue.

8. Diagnostic tools: Some laptops come with built-in diagnostic tools that can help identify motherboard problems. Check your laptop’s documentation or manufacturer’s website for any available tools.

If you suspect a problem with the laptop motherboard, it is recommended to consult a professional technician or contact the laptop manufacturer for further assistance. They will have the expertise to diagnose and repair any motherboard-related issues.