A BenQ “No Cable Connected” message almost always means the wrong input source is selected in the OSD menu — not that the cable is missing or broken. Manually select the input that matches your cable type (HDMI, DisplayPort, or DVI) to fix it.
- You manually select the correct input source in the OSD menu
- Your cable is firmly seated at both the monitor and GPU ends
- Your cable connects to the dedicated GPU port, not the motherboard
- Your graphics drivers and BIOS are up to date
- The cable is faulty or incompatible with the selected input
- You are plugged into the motherboard’s integrated graphics port instead of the GPU
- You are using a third-party adapter or docking station that breaks the signal
- Your laptop does not support DisplayPort Alt Mode or Thunderbolt for USB-C output
Why BenQ Monitors Show This Message
BenQ SW-series and many other BenQ monitors do not auto-detect the input source. When you plug in a cable, the monitor does not automatically switch to it. You have to tell the monitor which input to look at using the OSD (on-screen display) buttons on the front or underside of the panel.
This is the cause of the error in the majority of cases. The cable is fine — the monitor is just looking at the wrong input.
Step-by-Step Fixes
- Select the correct input source: Press the OSD button on your monitor, go to Input or Source, and choose the input that matches your cable — HDMI, DisplayPort, or DVI.
- Reseat both ends of the cable: Unplug and firmly re-plug the cable at the monitor and at the PC. DisplayPort cables in particular can feel seated when they are not fully locked.
- Check you are using the GPU port: Desktop PCs often have video ports on the motherboard and separate ones on the GPU. Use the GPU ports — usually lower on the back panel.
- Swap the cable: Try a different cable or a different cable type. If DisplayPort is not working, try HDMI instead to isolate whether the cable or port is the fault.
- Update your graphics driver: Outdated drivers can cause DisplayPort handshake failures. Download the latest driver from NVIDIA’s driver page or your GPU manufacturer’s equivalent.
- Factory reset the monitor: In the OSD, find the Reset or Factory Default option. This clears any misconfigured settings that could block signal detection.
Common Setups and What You Need
| Setup | Works? | Need | Note |
|---|---|---|---|
| PC GPU → DisplayPort → BenQ | Yes | Select DP input in OSD | Most reliable connection |
| PC GPU → HDMI → BenQ | Yes | Select HDMI input in OSD | Good fallback if DP fails |
| Laptop USB-C → BenQ HDMI | Maybe | DP Alt Mode or Thunderbolt support | Check if your laptop supports video over USB-C — see does USB-C support video |
| Laptop → Dock → BenQ | Maybe | Dock must pass video signal | Third-party docks often cause signal loss |
| Motherboard port → BenQ | No | Use GPU port instead | iGPU may be disabled in BIOS |
If you are connecting via USB-C and still getting no signal, check our guide on why USB-C to HDMI is not working for adapter-specific troubleshooting.
Bottom line: The BenQ “No Cable Connected” error is nearly always an input source mismatch, not a broken cable. Open the OSD, select the right input, and the picture should appear immediately. If it does not, swap the cable, confirm you are using the GPU port, and update your drivers before assuming the monitor or GPU has failed.