You boot the PC, the fans spin up, the power LED on the monitor goes from amber to blue — and then a small grey box floats over a black screen: Input Signal Out of Range (sometimes phrased as Out of Range, Mode Not Supported, or Cannot Display This Video Mode). The machine is fine. The monitor is fine. What's actually happening is that the GPU is outputting a video mode — a resolution plus refresh rate — that the panel's scaler refuses to lock onto. The monitor isn't broken; it's just saying no.
I've hit this dozens of times, most memorably after a Windows feature update silently reset a display driver and pushed my old Dell U2412M to 2560x1440, which that panel tops out at 1920x1200. The fix took 90 seconds once I knew the order of operations.
Cause 1: Refresh rate or resolution set higher than the panel supports
This is the one that bites 8 out of 10 people. Somewhere along the line — a driver update, a game that forced a custom mode, a KVM switch, or just a fresh Windows install — the GPU got told to output 144Hz on a 60Hz panel, or 4K on a 1080p screen. The monitor sees a signal it can't sync to and gives up.
The reason resolution isn't always the culprit: most monitors will happily downsample a slightly-too-high resolution via their scaler. Refresh rate is stricter. A 60Hz panel fed a 120Hz signal usually just shows the error, full stop.
The fix, in order
- Boot into Safe Mode. Hold Shift while clicking Restart, then Troubleshoot → Advanced options → Startup Settings → Restart → press 4. Safe Mode loads a basic display driver at 1024x768, which every monitor accepts.
- Once you're in, right-click the desktop → Display settings → Advanced display settings. Set the resolution to something conservative for your panel, like 1920x1080.
- Click Display adapter properties → Monitor tab → set Screen refresh rate to 60 Hz. Apply.
- Reboot normally. If the image comes back, you're done. If it doesn't, the bad mode is still being applied on boot — go to step 5.
- If the mode persists after reboot, open Device Manager in Safe Mode, expand Display adapters, right-click your GPU, and uninstall the driver (check "Delete the driver software for this device"). Reboot to let Windows install a generic driver, then reinstall the vendor driver fresh.
If you're on a laptop with an external monitor and can't see the internal screen either, plug into a TV with the same cable. TVs are far more forgiving with odd modes, and you'll get a visible desktop to work from.
Cause 2: A custom resolution or EDID override left behind by a tool
Custom Resolution Utility (CRU), NVIDIA Control Panel's custom resolutions, and AMD's Virtual Super Resolution all write modes the monitor doesn't natively advertise. When the monitor hot-plugs (or wakes from sleep) and re-reads its own EDID, it rejects whatever the GPU is offering.
This one is nasty because it survives a driver reinstall. The override lives in the registry and in the GPU's persistent mode list.
The fix
Boot to Safe Mode again, then:
- Open CRU and click Reset-all.exe (shipped alongside it). Reboot.
- For NVIDIA: NVIDIA Control Panel → Change resolution → Customize → delete every custom entry.
- For AMD: Adrenalin → Display → Custom Resolutions → remove anything non-standard.
- For Intel: Graphics Command Center → Display → Custom Resolutions → delete the lot.
If you can't get into Windows at all, boot from a Linux live USB and run the display at a safe mode, which resets the GPU's mode table independently of Windows.
Cause 3: Cable or adapter can't carry the signal you're sending
Less common but real. A single-link DVI cable maxes out around 1920x1200 at 60Hz. A cheap HDMI 1.4 cable won't carry 4K at 60Hz — you need HDMI 2.0 or better. DisplayPort-to-HDMI adapters are a frequent offender: many only handle 1080p60, and the monitor throws the out-of-range error when it receives a 1440p or 4K signal through one.
You'll usually see this after upgrading a monitor without swapping the cable. The old DisplayPort cable that ran your 1080p screen doesn't have the bandwidth for 1440p at 144Hz.
The fix
Swap to the cable that came in the monitor box, or buy a certified one. For 1440p at 144Hz you want DisplayPort 1.2 or better. For 4K at 60Hz, DisplayPort 1.2 or HDMI 2.0. For 4K at 120Hz+, DisplayPort 1.4 or HDMI 2.1.
Also check the physical connection. A DisplayPort cable that's half-seated will negotiate a fallback mode that the monitor might reject. Push it in until it clicks, and latch the DP clips.
Quick reference
| Symptom | Likely cause | Fastest fix |
|---|---|---|
| Error appears right after a Windows or GPU driver update | Refresh rate reset by driver | Safe Mode → set 60Hz → reboot |
| Error only on cold boot, works after monitor power-cycle | Custom resolution / EDID override | Run CRU Reset-all.exe |
| Error after swapping monitors with the same cable | Cable bandwidth too low | Use DP 1.2+ or HDMI 2.0+ cable |
| Error on one input only (e.g. HDMI, but DP works) | Input port's scaler limit | Switch to DP or lower the mode |
| Error with a KVM or adapter in the chain | KVM/adapter max mode exceeded | Bypass adapter, test direct |
| Error with no obvious trigger, suddenly | Panel or scaler failure | Test monitor on another PC to confirm |
Rule of thumb: if the monitor worked yesterday, it's a software mode issue — not a dead panel. If it never worked on this cable, it's the cable or the adapter. If it never worked at all, check the monitor's spec sheet before assuming anything is broken.
One more thing worth knowing: some monitors have a "DisplayPort version" setting buried in the OSD (under System or Input). If it's set to 1.1 and you're sending a 1.2+ signal, you'll get the out-of-range error on some models. Flip it to 1.2 or 1.4 and the image comes back instantly. This trips up owners of certain Dell and LG panels more than any other single setting.