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Fix a laptop screen that has lines

We'll rule out software and cable, then isolate the cause—loose cable, panel damage, or GPU—or tell you when to call a pro.

Troubleshooting · Home maintenance
10–30 min
What you'll need
  • External monitor and cable (to test)
  • Screwdriver set (if reseating cable)
Step 1 of 5

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Steps

Goal: Rule out GPU and driver, then isolate cable or panel.

  • Connect an external monitor. If it has no lines, the internal display or cable is the issue.
  • Good: You have isolated the cause. Proceed to Try external monitor.
  • Bad: If both have lines, update drivers and try Safe Mode.

Try external monitor

Goal: Determine whether the GPU outputs a clean image.

  • Connect an external monitor. Check if it has lines.
  • If the external is clean, the internal display cable or panel has failed. If the lines change with lid angle, the cable is likely loose.
  • Good: Cause isolated. Reseat the cable if comfortable, or call a technician.
  • Bad: Both have lines—update drivers.

Update drivers

Goal: Rule out driver-related artifacts.

  • Update graphics drivers from the manufacturer site. Boot in Safe Mode to see if the lines disappear.
  • Good: Lines gone in Safe Mode—driver or software conflict. Update or reinstall the driver.
  • Bad: Lines persist—GPU or panel may have failed. Call a technician.

When to get help

Call a technician if:

  • The external monitor is clean but the internal has lines.
  • You are not comfortable opening the laptop to reseat the cable.
  • The panel has physical damage—replacement needed.

Verification

  • The screen displays without lines.
  • External monitor test confirms GPU or internal display status.
  • Cable reseated or panel replaced if that was the fix.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. External monitor test Connect external—if clean, internal cable or panel failed.
  2. Update drivers Install latest graphics driver.
  3. Reseat cable (if comfortable) Open laptop and reseat display cable at both ends.
  4. Call a pro Panel damage or cable reseat failed—technician needed.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Whether external monitor has lines
  • Whether lines change with lid angle
  • Laptop model
  • Steps already tried

Does the external monitor have lines?

If external is clean, the internal display or cable is the issue.

Connect external monitor. External clean: internal cable or panel—reseat cable or call technician. External has lines: GPU or driver—update drivers.

Yes No

You can change your answer later.

Do the lines change when you move the lid or apply light pressure?

Changing lines often indicate a loose cable.

Gently flex the lid. Lines change: loose cable—reseat if comfortable, or call technician. Lines fixed: panel damage—call technician for replacement.

Yes No

You can change your answer later.

Update drivers and boot Safe Mode

Update graphics driver. Boot in Safe Mode. If lines disappear in Safe Mode, driver or software conflict. If lines persist, GPU may have failed—call a technician.

Done

Reseat display cable

Open laptop per model guide. Unplug and replug display cable at motherboard and panel. Only if comfortable with disassembly. If not, call a technician.

Done

Call a technician

Internal display has lines, external is clean. Cable reseat or panel replacement needed. Opening the laptop requires a professional.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a laptop screen have lines?
Loose display cable, damaged panel, failing GPU, or driver issue. Test with external monitor first. Lines that change with lid angle often mean a loose cable.
Can I fix laptop screen lines myself?
You can try updating drivers and reseating the display cable if you are comfortable opening the laptop. Panel damage or a failed panel needs replacement—call a technician.
When should I call a technician for screen lines?
If the external monitor has no lines but the internal does—the cable or panel is at fault. Reseating the cable or replacing the panel requires opening the laptop.

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