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Fix a Chromebook that has display that has wrong overscan

We'll adjust overscan in Settings for external displays, check the monitor OSD, or tell you when to call support.

Troubleshooting · Home maintenance
5–10 min
What you'll need
  • Chromebook
  • External monitor or TV (for overscan adjustment)
Step 1 of 6

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Steps

Goal: Confirm the symptom, adjust overscan in Chromebook Settings for external displays, or use the monitor OSD.

  • Check whether the image is cropped at the edges or has black borders.
  • Good: You have confirmed the symptom. Proceed to Chromebook overscan or Monitor OSD.
  • Bad: Unclear—open Settings > Device > Displays and check which display has the problem.

Chromebook overscan

Goal: Adjust overscan in Chromebook Settings for external displays in extended mode.

  • Click the status area (clock), then the gear icon. Settings > Device > Displays.
  • Select the external display (not the built-in). Overscan is available in extended display mode, not mirror mode.
  • Scroll to Overscan. Use the arrow keys to shrink (if the image is cropped) or expand (if there are black borders). Use Shift + arrow keys to move the image position.
  • Good: The image fits the screen. Done.
  • Bad: Overscan option does not appear—you may be in mirror mode. Use the monitor OSD or switch to extended mode.

Monitor OSD

Goal: Use the monitor or TV OSD to adjust overscan.

  • Use the monitor buttons to open the OSD. Look for Overscan, Picture Size, or Aspect Ratio.
  • Set to “Just Scan” or “1:1” to disable overscan and show the full image. Some TVs call this “Full Pixel” or “Screen Fit.”
  • Good: The image fits the screen. Done.
  • Bad: No OSD control or image still wrong—try a different cable or call support.

When to get help

Call support if:

  • Overscan controls do not appear for your external display in extended mode.
  • The image stays cropped after adjusting Chromebook and monitor settings.
  • You have tried a different cable and the problem persists.

Verification

  • The image fits the screen with no cropped edges.
  • No black borders around the image.
  • Overscan is adjusted in Chromebook Settings or monitor OSD.
  • Resolution is set to recommended.

Escalation ladder

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

  1. Chromebook overscan Settings > Device > Displays > Overscan; use arrow keys.
  2. Monitor OSD Use monitor OSD for overscan or picture size.
  3. Cable and resolution Try different cable; confirm resolution.
  4. Call support Overscan controls do not appear or image stays cropped.

What to capture if you need help

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

  • Chromebook model
  • External display model
  • Display mode (extended or mirror)
  • Steps already tried

Is the problem on the built-in display or an external monitor/TV?

Overscan controls apply to external displays.

Check Settings > Device > Displays. Built-in: built-in screens rarely have overscan issues—check resolution and display size. External: use Chromebook overscan or monitor OSD.

Built-in External

You can change your answer later.

Check resolution and display size

Built-in display overscan is rare.

Settings > Device > Displays. Set resolution to recommended. Adjust display size. If edges are still cropped, it may be a different issue—call support.

Done

Are you in extended display mode?

Overscan is available in extended mode, not mirror mode.

Settings > Device > Displays. Check display mode. Extended: overscan option should appear—select the external display and scroll to Overscan. Mirror: use the monitor OSD for overscan or switch to extended.

Extended Mirror

You can change your answer later.

Does the Overscan option appear?

Select the external display and scroll down.

Settings > Device > Displays. Select the external display. Scroll to Overscan. Appears: use arrow keys to shrink or expand; Shift + arrow keys to move. Does not appear: use monitor OSD or try a different cable.

Yes No

You can change your answer later.

Adjust overscan

Use arrow keys to shrink (if cropped) or expand (if black borders). Shift + arrow keys to move. When the image fits the screen, you are done.

Done

Use monitor OSD

Use monitor or TV buttons to open OSD. Look for Overscan, Picture Size, or Aspect Ratio. Set to "Just Scan" or "1:1" to disable overscan. If image fits, you are done. If not, try a different cable or call support.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a Chromebook display have wrong overscan?
External monitor or TV crops the image (overscan) or shows black borders (underscan). Chromebook has overscan controls for external displays in extended mode. Mirror mode does not offer overscan in Settings.
Can I fix wrong overscan myself?
Yes. For external displays in extended mode, use Settings > Device > Displays > Overscan. Use arrow keys to adjust. For mirror mode, use the monitor or TV OSD. Built-in display rarely has overscan issues.
When should I call support for wrong overscan?
If overscan controls do not appear for your external display, or the image stays cropped after adjusting Chromebook and monitor settings. The display or cable may need repair.

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