FAQ
TL;DR: Reseating connectors restored the display for about 14 days; the intermittent “no signal” returned. “Check another tab/integrated.” [Elektroda, kokapetyl, post #16846358]
Why it matters: This FAQ helps PC users fix random “no signal” on boot by isolating GPU, cable/adapter, PSU, and firmware causes.
Quick Facts
- PC spec in thread: Windows 10, GTX 1060 6 GB, i7‑4770, 16 GB RAM, ASRock H81M‑HDS, Seasonic S12II 520 W. [Elektroda, AksmaitnyGrzmot, post #16846205]
- Safe test mode: 1024×768 at 60 Hz via F8 and then raise to native 1920×1080. [Elektroda, kiss39, post #16846215]
- Symptom pattern: LG shows “no signal” instead of BIOS/Windows logos right after power‑on. [Elektroda, AksmaitnyGrzmot, post #16846320]
- Firmware/storage checks: Reset CMOS; even a disk, mouse, or keyboard can block POST; check SMART. [Elektroda, safbot1st, post #16846231]
- Isolation tip: Use motherboard graphics output, remove PCI‑E GPU, and try another known‑good monitor. [Elektroda, safbot1st, post #16847690]
Why does my monitor say “No signal” at boot randomly?
Loose GPU seating, flaky cable/adapter, or a failing GPU can interrupt the signal before BIOS appears. Test with integrated graphics to isolate the GPU and link path. This aligns with the advice to check the card, connection, cable, and iGPU first. [Elektroda, kokapetyl, post #16846358]
How do I quickly tell if the GPU or the monitor/cable is at fault?
Connect the monitor to the motherboard video port, remove the PCI‑E GPU, and boot. If video returns, the add‑in GPU or its cable/adapter is suspect. Also try a second, known‑good monitor to rule out the display. [Elektroda, safbot1st, post #16847690]
Can a video adapter or cable really cause a no‑signal on startup?
Yes. Marginal adapters or loose connectors can break the link during initialization. Reseat or replace the adapter and cable, and ensure firm connections at both ends. Connection quality was highlighted as a direct contributor to no‑signal symptoms. [Elektroda, kokapetyl, post #16846433]
How do I use integrated graphics on an ASRock H81M‑HDS to test?
Power down, unplug, and move the display cable from the GPU to the motherboard’s video output. Remove the PCI‑E card for a clean iGPU boot. If it posts with iGPU, focus on the card, its power, or its cable path. [Elektroda, safbot1st, post #16847690]
Should I reset CMOS, and what does it do?
Yes. A CMOS reset restores default firmware settings that might block POST or video init. Pull power, clear CMOS per the board manual, then load defaults. “Reset CMOS and restore default settings.” [Elektroda, safbot1st, post #16846231]
What is POST, and how can the HDD LED help?
POST is the Power‑On Self Test that checks hardware before boot. If the HDD LED never blinks, the system may not reach disk init. A blinking LED suggests it passed some POST stages, narrowing the fault to display path. [Elektroda, lazania, post #16847478]
How can a small speaker (buzzer) help diagnose this?
Attach a system buzzer to the motherboard. Remove the GPU and power on. Beep codes indicate missing GPU or other faults and confirm POST activity without a display. The prompt “Squeaks?” hints at listening for those codes. [Elektroda, safbot1st, post #16846221]
Could the power supply be the reason there’s no image?
Yes. An underperforming or unstable PSU can prevent GPU initialization even if fans spin. Helpers flagged the PSU as a potential culprit on this power‑hungry setup. Swap in a known‑good unit to test. [Elektroda, safbot1st, post #16846304]
It worked for almost two weeks after reseating cables. What does that indicate?
Improvement after reseating points to an intermittent contact issue—connector oxidation, loose PCI‑E seating, or a weak adapter. Stability for about 14 days is a concrete clue that physical connections are central. [Elektroda, AksmaitnyGrzmot, post #16846205]
How do I check disk SMART quickly to rule out storage hangups?
Install CrystalDiskInfo and read SMART status for each drive. A failing disk can stall POST or OS handoff, appearing as a display issue. Capture the report for further diagnostics. [Elektroda, safbot1st, post #16846231]
What resolution and refresh should I try if Windows loads but there’s no picture?
Boot into the F8 troubleshooting mode and set a safe 1024×768 at 60 Hz. Reboot and then raise it to your panel’s native 1920×1080 if stable. This helps if the driver chose an unsupported mode. [Elektroda, kiss39, post #16846215]
Can USB devices really block boot and cause no‑signal symptoms?
Yes. Faulty USB devices, including a mouse or keyboard, can hang POST. Disconnect non‑essentials and retest. This edge case often masquerades as a video failure. [Elektroda, safbot1st, post #16846231]
What is SMART, in simple terms?
SMART stands for Self‑Monitoring, Analysis and Reporting Technology. Drives use it to report health metrics that predict failure. Reviewing SMART helps spot storage problems that stall boot. [Elektroda, safbot1st, post #16846231]
3‑step “No Signal” quick isolation checklist
- Move the cable to the motherboard video port and remove the PCI‑E GPU.
- Boot with a second, known‑good monitor or cable.
- If video returns, focus on the GPU, its power leads, or the adapter path. [Elektroda, safbot1st, post #16847690]
My PSU and GPU are only about 2 months old—does that rule them out?
No. New parts can still be faulty or sensitive to connections. The thread’s PSU and GPU were recent, yet symptoms persisted. Always test with substitutions and reseating, regardless of part age. [Elektroda, AksmaitnyGrzmot, post #16846205]
