Here is a list of troubleshooting steps that may help resolve display issues with vertical or horizontal lines:

1. Check the video cable – Make sure the connection is secure and the cable is not frayed, squished, bent, or torn.
2. Check the video card – Make sure the card is properly seated and properly screwed in.
3. Check the monitor – Make sure the monitor is plugged in and that all the proper connections are secure.
4. Check the power supply – Make sure that the power supply is plugged in and that all connections are secure.
5. Check the system memory – Make sure all modules are properly seated and connected.
6. Test the laptop on an external monitor – If a separate monitor works with the laptop, the issue is likely with the laptop’s display and not a hardware issue.