Fix “No Signal” on Your Monitor: the Safe 3-Step Check (Cable → GPU → BIOS)

If your screen suddenly says “No Signal” (中文常见提示：“无信号”), you’re not alone. It usually comes down to something simple—an input mismatch, a tired cable, or a setting that got nudged. Below is a friendly, non-technical three-step to get you back to work or gaming, fast. And if anything feels tricky, we’re right here in Burswood to help.

TL;DR

• Start with cables & inputs (HDMI/DisplayPort).

• Confirm you’re plugged into the graphics card, not the motherboard.

• If you can enter BIOS, check Primary Display and reset to defaults if needed.

• Still stuck? Pop in and we’ll test with known-good parts. 👍

1) Cables & Ports: HDMI/DisplayPort basics

Why this matters: Most “No Signal” cases are a simple handshake or input issue.

• Check the input source on the monitor (HDMI1 vs HDMI2 vs DP). Use the monitor’s menu and cycle inputs.

• Reseat both ends of the cable (monitor and PC). Push until fully home—DisplayPort especially likes a firm click.

• Try another port and a known-good cable. If you have both HDMI and DP, test the other standard.

• Avoid flaky adapters (e.g., cheap DP→HDMI). Go direct cable-to-port when possible.

• Look for bent pins or loose latches. Replace any cable with damage.

• High-refresh setups: 1440p/240 Hz or 4K/144 Hz often need DP 1.4/2.0 or HDMI 2.1 quality cables. An older cable may cap refresh or fail to sync.

2) Graphics Card Path: make sure you’re in the right hole 😅

Why this matters: If you have a dedicated GPU, the monitor must plug into the GPU’s ports, not the motherboard’s.

• Check where you’ve plugged in.

  • Dedicated GPU present? Use the GPU’s HDMI/DP ports (typically lower on the back and horizontal).

  • No dedicated GPU? Use the motherboard video-out only if your CPU has integrated graphics.

• Do the fans spin on the GPU at power-on? (Some remain off at idle—brief spin at start is normal.)

• Test with integrated graphics (if available). Move the cable to the motherboard port.

  • Picture works on iGPU but not on GPU? The issue may be the card, its slot, the power connectors, or drivers—this is a good time to let us bench-test safely.

• Power connectors: Many GPUs need one or two 6/8-pin PCIe plugs from the PSU. If you’re unsure, don’t open the case—we’ll check it for you.

✅ Good sign: You get a display via motherboard but not the GPU.
❌ Red flag: No display from any port or any cable—could be PSU, GPU, or motherboard.

3) BIOS/UEFI Display Settings (safe checks only)

If you can see the BIOS screen (tap Del/F2 during startup):

• Reset to Defaults (often “Load Optimised Defaults”). This won’t delete your files.

• Look for Primary Display / Initial Display Output and set to PCIe/PEG when using a dedicated GPU.

• Disable Fast Boot temporarily. It can skip device checks that help a stubborn monitor handshake.

• Save & Reboot. Test again on the GPU port.

⚠️ Avoid jumper/battery removals or risky firmware flashes at home. If a BIOS update is required, we’ll do it safely after backup and hardware checks.

Real-World Examples from Our Bench

• Auckland gamer, 144 Hz monitor: “No Signal” only at 144 Hz over HDMI. Swapped to a proper DP 1.4 cable—stable 144 Hz instantly.

• Small biz desktop, dual screens: Both cables were fine, but the PC was plugged into the motherboard while a GTX card sat unused. Moved both cables to the GPU—problem solved.

Quick self-checks & tips (no tools needed)

• Try the PC on a different monitor or TV (and vice versa).

• Test a known-good cable that works on another device.

• Make sure the monitor is powered on (some power lights are tiny).

• Lower the refresh rate temporarily if you can reach Windows (e.g., 60 Hz) and then step back up.

• If Windows loads (sound notifications) but screen is blank, try Win + P and select “PC screen only”.

When to call a pro

• No display from any port/cable/monitor.

• You suspect power or graphics card failure.

• You’re not comfortable opening the case or changing BIOS options.

• You need a BIOS update, PSU/GPU test, or data-safe diagnosis.

What we do at AEPC (Auckland East PC)

• Same-day diagnosis with known-good HDMI/DP cables, test monitors, and bench GPUs.

• GPU/PSU testing and slot checks without risking your data.

• BIOS/UEFI help (safe defaults, firmware updates where appropriate).

• Parts sourcing (quality cables, GPUs, PSUs) with clear quotes.

• Warranty & reporting: Clear findings, repair options, and workmanship warranty.

Prevention & best practices

• Use quality HDMI/DP cables matched to your refresh/resolution.

• Label monitor inputs (HDMI1/DP) so family members select the right one.

• Avoid yanking cables; seat DP until it clicks.

• Keep dust down; ensure good airflow around the GPU.

• After big Windows/GPU driver changes, reboot to refresh handshakes.

Need help now? Pop in or book

AEPC – Auckland East PC
📍 9/28 Torrens Road, Burswood, Auckland 2013
📞 0279-088880
📧 akleastpc@gmail.com
🕘 Mon–Fri: 9:00 AM – 5:00 PM
🕘 Sat & Sun: 9:00 AM – 4:00 PM (reservation required)

We’ll isolate the fault quickly and get your display back—often the same day.

FAQ

Q1: HDMI or DisplayPort—what’s better for gaming?
Both work well. For high refresh (144–240 Hz) and variable refresh (G-Sync/FreeSync), DisplayPort is often more flexible. For TVs or consoles, HDMI is standard.

Q2: Does a “No Signal” mean my GPU is dead?
Not necessarily. Cables, ports, inputs, and BIOS priorities are more common. If the iGPU works but the GPU doesn’t, we’ll test the card on our bench to confirm.

Q3: Will resetting BIOS erase my files?
Resetting to defaults doesn’t affect your data. It only reverts firmware settings.

Q4: Can a weak PSU cause “No Signal”?
Yes—if the GPU isn’t powered properly, you may get no display. We can verify with a known-good PSU and load tests.

Q5: My monitor works via HDMI but not DP (or vice versa). Why?
Often a cable spec or handshake issue. Try another certified cable and reseat firmly. Some high-refresh modes require DP.

Q6: Do you offer onsite pickup in East Auckland?
Yes—ask us about pickup/drop-off options around East/South Auckland.

Q7: Will you help choose the right cable?
Absolutely. Bring in your monitor model and goals (e.g., 1440p/165 Hz) and we’ll match the right HDMI/DP cable.