Your laptop connects to a TV or external monitor through a USB-C hub, and the image appears—but the edges are missing.
The Windows taskbar may be cut off. The macOS menu bar may sit outside the visible area. Desktop icons near the corners disappear, or the entire picture looks slightly zoomed in.
This problem is usually called overscan.
Overscan happens when the display enlarges the incoming image and hides part of it beyond the screen borders. It is especially common with TVs because some television picture modes treat HDMI signals like video content instead of a computer desktop. Apple describes overscan as a picture whose margins are hidden beyond the screen boundary, as though the image has been zoomed in.
The USB-C hub may appear to cause the problem because the cropping starts after you connect through HDMI. However, the real cause can be the TV picture mode, Windows or macOS resolution, GPU scaling, HDMI input settings, or the way the display identifies the new signal.
Identify the Problem in 30 Seconds
Look at all four edges of the screen.
| What You See | Most Likely Cause |
|---|---|
| Taskbar, menu bar, or corners are missing | Overscan |
| Black borders around the picture | Underscan |
| Everything fits, but text and icons are too large | Operating-system scaling |
| Image is stretched horizontally or vertically | Wrong aspect ratio |
| Picture is small and centered | Incorrect resolution or scaling mode |
| Cropping happens only through the hub | HDMI negotiation, hub, cable, or input settings |
| Cropping also happens with direct HDMI | TV, monitor, or computer display settings |
The distinction matters because changing Windows text scaling will not normally fix a television that is applying overscan.
Start with the TV or Monitor—not the Hub
When the image is visible but cropped, check the display’s picture settings first.
Open the TV or monitor menu using its remote control or physical buttons. Look for settings named:
- Screen Fit
- Just Scan
- Fit to Screen
- 1:1
- Full Pixel
- Native
- PC Mode
- Computer Mode
- Aspect Ratio
- Zoom
- Overscan
- Picture Size
- Screen Fill
- Format
Apple’s official overscan guide recommends checking the display for settings such as underscan, zoom, aspect ratio, computer mode, screen fit, screen fill, and format.
For a computer connected through HDMI, try these settings first:
Screen Fit / Just Scan / 1:1 / Full Pixel / PC Mode
Avoid picture modes such as:
- Zoom
- Cinema Zoom
- Wide Zoom
- Overscan On
- Stretch
These modes may enlarge the picture and hide desktop edges.
Rename the HDMI Input to “PC”
Some TVs change their processing when an HDMI input is labeled PC.
This may:
- Disable overscan
- Preserve the full desktop
- Improve text clarity
- Reduce unnecessary image processing
The exact name varies by TV brand, so check the display manual if the option is not obvious.
Fix Cropping on Windows
If the TV or monitor is already set to Screen Fit or PC Mode, check Windows next.
Go to:
Settings → System → Display
Select the affected TV or monitor before changing anything.
Use the Recommended Resolution
Under Display resolution, select the option marked Recommended.
For example:
- 1920 × 1080 for a Full HD display
- 3840 × 2160 for a 4K display
Microsoft recommends using the display’s suggested resolution. Lower-than-native resolutions can make the picture smaller, stretched, bordered, or less sharp.
Check Windows Scale
Under Scale & layout, choose the recommended scale setting.
Common values include:
- 100%
- 125%
- 150%
Scaling changes the size of text and apps. It does not normally change the physical video boundary.
Therefore:
- Missing screen edges = likely overscan
- Large icons but all edges visible = likely Windows scaling
Do not use a custom Windows scale value as the first fix for cropped edges.
Check GPU Scaling
If the television has no Screen Fit or Overscan control, open your graphics software.
Depending on the computer, look for:
- NVIDIA Control Panel
- AMD Software
- Intel Graphics Command Center
- Your laptop manufacturer’s display utility
Possible settings include:
- Adjust desktop size and position
- HDMI Scaling
- Custom Scaling
- Maintain Aspect Ratio
- Full-screen Scaling
- Center Image
Start with:
Maintain Aspect Ratio or No Scaling
Use a custom underscan slider only when the display itself cannot show the complete image.
Fix Cropping on Mac
On Mac, go to:
Apple menu → System Settings → Displays
Select the connected TV or monitor.
Check:
- Resolution
- Refresh rate
- Display preset
- Underscan, if available
Apple advises selecting the TV in Display Settings and adjusting the Underscan control when that option is available. If the Mac does not show an Underscan control, Apple recommends checking the TV’s own settings or changing the Mac display resolution.
Try the Default Resolution First
Use the display’s default or recommended resolution before testing scaled options.
If the picture fits at one resolution but becomes cropped at another, the TV may be applying different picture settings to different signal formats.
That is a sign to check the TV’s aspect-ratio or Screen Fit setting again rather than leaving the Mac at a lower resolution.
Why Changing Resolution Sometimes “Fixes” It Temporarily
Users often lower the resolution from 4K to 1080p and notice that the desktop suddenly fits.
That does not necessarily mean the original resolution was unsupported.
Changing the resolution can cause the TV to recognize a different video timing and apply another picture mode. The display may stop overscanning at 1080p while continuing to overscan at 4K.
A better fix is to:
- Restore the display’s native resolution.
- Open the TV picture-size settings.
- Enable Screen Fit, Just Scan, 1:1, or PC Mode.
- Save the setting for the active HDMI input.
This preserves image quality instead of using a lower resolution to hide the original configuration problem.
Run the Direct-Connection Test
This test reveals whether the hub is really involved.
Test A: Through the Hub
Connect:
Laptop → USB-C Hub → HDMI Cable → TV or Monitor
Note whether:
- All four edges are visible
- The taskbar is complete
- The aspect ratio looks correct
- The selected resolution is native
Test B: Direct Connection
Connect the laptop directly to the same display using a compatible HDMI or USB-C video connection.
Keep the same:
- HDMI input
- Resolution
- Refresh rate
- Display picture mode
Interpret the Result
| Result | Likely Cause |
|---|---|
| Both connections are cropped | TV, monitor, OS, or GPU scaling |
| Only the hub connection is cropped | Hub, adapter, cable, or signal negotiation |
| Another HDMI input fixes it | Input-specific picture settings |
| Another cable fixes it | Cable or connector issue |
| PC Mode fixes it | TV video processing or overscan |
| Lower resolution fixes it only temporarily | Display mode changes by signal timing |
If direct connection works correctly, reconnect the hub after restarting both the laptop and display. This can refresh the display handshake.
Check the HDMI Cable and Input
A cropped picture is more commonly caused by scaling than by a damaged HDMI cable. However, changing the cable can alter which resolution or display mode is successfully negotiated.
Test:
- Another HDMI cable
- Another HDMI input on the TV
- A shorter cable
- The same cable with a different computer
- The hub with a different display
For 4K TV or monitor connections, a 4K HDMI cable for TV should support the resolution and refresh rate required by the setup.
The Lention VC-HH20 supports HDMI 2.0 and up to 4K@60Hz; the currently available 3m braided version can be used when testing or replacing the display cable.
Changing the cable will not directly disable overscan, but it can help rule out an unstable or limited signal path.
When the USB-C Hub Matters
The hub becomes a stronger suspect when:
- Direct connection fits correctly
- The hub reports a different resolution
- The display identifies the connection as a different device type
- Cropping returns after sleep or reconnecting
- Another hub or adapter works normally
- The current hub does not support the desired output mode
A USB-C hub with HDMI output should support the display resolution you intend to use, and the laptop’s USB-C port must support video output through DisplayPort Alt Mode or a compatible technology.
For portable Full HD or 4K@30Hz setups, the Lention CB-C25 provides HDMI output, three USB 3.0 ports, and Gigabit Ethernet. Its product page states support for up to 4K@30Hz and lower resolutions, with DP Alt Mode required on the host device. Current availability shows gray and rose gold options, while blue is out of stock.
A new hub should not be presented as a guaranteed overscan fix. Overscan is often controlled by the TV or operating system rather than the hub itself.
Best Fix by Symptom
| Symptom | Best First Action |
|---|---|
| Desktop edges cut off on TV | Enable Screen Fit, Just Scan, or PC Mode |
| Windows taskbar missing | Check TV overscan, then native resolution |
| Mac menu bar outside screen | Use Mac Underscan or TV picture-size controls |
| Black borders around image | Reduce underscan or choose native aspect ratio |
| Everything appears too large | Change Windows or macOS scaling |
| Picture is stretched | Set aspect ratio to Original, Native, or 16:9 |
| Only hub connection is cropped | Test direct connection, cable, and HDMI input |
| 4K cropped but 1080p fits | Check picture mode separately at 4K |
FAQ
Why is my TV screen cropped when using a USB-C hub?
The TV may be applying overscan to the HDMI signal. Change the TV picture size to Screen Fit, Just Scan, Full Pixel, 1:1, or PC Mode.
Is overscan caused by the USB-C hub?
Not always. The hub can change how the signal is identified, but overscan is commonly applied by the TV or monitor. Compare the hub connection with a direct connection.
Why is the Windows taskbar cut off?
The TV is probably enlarging the HDMI image beyond the visible screen. Fix the TV’s overscan or aspect-ratio setting before changing Windows text scaling.
What is the difference between scaling and overscan?
Scaling changes the size of text, apps, or the rendered desktop. Overscan enlarges the entire video image and hides its outer edges.
Why does 1080p fit while 4K is cropped?
The TV may store or apply different picture settings for different resolutions. Enable Screen Fit or PC Mode while the TV is receiving the 4K signal.
Should I use 100% Windows scaling?
Use the Windows-recommended scale for readability. Scaling is not usually the correct fix when actual screen edges are missing.
Can a new HDMI cable fix overscan?
A cable does not directly control overscan, but replacing it can help rule out signal negotiation or resolution issues.
Final Thoughts
When a TV or monitor image is cropped through a USB-C hub, start with the display—not with Windows icon size or a new hub.
Use this order:
TV Screen Fit or PC Mode → Native Resolution → OS Scaling → GPU Scaling → Direct Connection → Hub and HDMI Cable
If the edges are missing, the most likely cause is overscan. If all edges are visible but text and apps are too large, the issue is system scaling.
A compatible USB-C hub with HDMI output and 4K HDMI cable for TV can provide the required video connection, but the final picture size still depends on the laptop, display resolution, HDMI input, and TV picture mode.
