If your PC is running but the monitor stays blank, the fault lies somewhere in the chain between them: the monitor and its input setting, the cable, the output port, the graphics card, the RAM or the CPU. Work from the screen backwards. Check the monitor's input source, then the cable, then whether the cable is plugged into the graphics card rather than the motherboard.
Is the PC really on, and what is the monitor telling you?
First confirm the computer is alive. Look for spinning fans, a lit power LED and drive activity. If your keyboard has a Caps Lock light, tap it: if the light toggles, the system is running. Then read the monitor itself, because its behaviour separates a display problem from a PC problem.
| What the monitor shows | What it usually means |
|---|---|
| No light at all on the monitor | Monitor power fault, power cable or switch |
| "No signal" or "Check cable" | No picture arriving: wrong input, bad cable, wrong port, or the PC is not completing start-up |
| "Input not supported" or "Out of range" | PC is sending a resolution or refresh rate the monitor cannot show |
| Standby light, screen black | Monitor is asleep because it detects nothing, or the PC is in sleep mode |
| Picture appears briefly, then blank | Driver, refresh rate or an unstable connection |
"No signal" is the most common message and the least specific. It tells you the monitor is working and is receiving nothing. Everything from a loose plug to a dead graphics card produces it, so the steps below go from the cheapest check to the most involved.
Which quick checks come before opening the PC?
Most blank-screen cases end here. Each of these takes under a minute, and none involves tools. Test after every step so you know exactly what changed.
- Check monitor power and brightness. Make sure the monitor's power cable is firm and the brightness has not been turned to zero.
- Select the correct input. Press the monitor's input button and step through HDMI, DisplayPort, DVI and VGA. Auto-detect sometimes picks wrongly.
- Reseat the cable at both ends, or swap it for a different one. A bent or worn connector is a common failure, especially on HDMI.
- Try another port on the graphics card and on the monitor.
- Test the monitor elsewhere. Connect it to a laptop. If it displays there, the monitor is fine. A different monitor or TV on your PC is an equally good test.
- Press Windows + Ctrl + Shift + B. This restarts the graphics driver and you should hear a short beep if Windows is running.
- Press Windows + P, then choose "PC screen only". A previous setting of "Second screen only" leaves one monitor blank.
- Disconnect extra displays. A second monitor or a TV can confuse the primary display.
A note about adaptors. Turning a digital HDMI or DisplayPort signal into analogue VGA needs an active converter with its own chip, and a bare cable that claims to do the job often fails. Going the other way, from VGA to HDMI, needs a powered converter too. If a new cable or adaptor has just been introduced, it is the first suspect.
Why is the cable in the wrong port such a frequent cause?
On a PC with a dedicated graphics card, the motherboard's video outputs are usually switched off, so a cable plugged in there carries nothing. The card's own ports sit lower on the back of the case, in the horizontal slot area. The mistake is easy to make after a rebuild, a cleaning or a graphics upgrade.
- With a graphics card installed: connect the monitor to the card's ports, not the motherboard's.
- With no graphics card: use the motherboard's ports, provided the CPU has integrated graphics.
- After a new card: check its power cables are fully inserted, and that its fans spin when the PC starts.
- After removing a card: move the monitor cable to the motherboard.
If a card seems fine but is the suspect, our graphics card problems guide shows how to prove whether it has failed.
How do you test the RAM, graphics card and CPU?
If the PC runs but never reaches the point of sending a picture, the start-up test is failing before the graphics stage. A memory fault is the most common reason, because a PC with unseated or bad RAM will not complete the test. Switch off and unplug before you begin.
- Reseat the RAM. Remove all modules, then fit one into the slot the manual recommends. Test each module and each slot separately.
- Reseat the graphics card and its power cables. Look for dust or scorch marks on the gold contacts.
- Try integrated graphics. If the CPU has them, remove the card and connect the monitor to the motherboard. A picture proves the card is the problem.
- Clear the CMOS. Use the board's clear jumper or remove the coin battery for a few minutes. This resets BIOS settings that may be blocking the display, particularly after a memory profile change.
- Check the CPU power cable and the 24-pin motherboard connector.
- Be patient on a new or changed build. After new RAM or a BIOS reset, many boards, especially DDR5 platforms, retrain their memory and may show a blank screen for a minute or longer before the first picture.
Any beeping or debug lights give you extra information. Our guides on desktop beeping and not booting and RAM not detected help decode them. If the PC does not even start, see the desktop not turning on guide.
What if Windows loads but the screen goes blank later?
That points to software, settings or cabling rather than a dead component. Common triggers include a graphics driver update, a refresh rate that is too high for the monitor or cable, and monitors that lose their DisplayPort handshake after sleep. Windows itself is probably fine.
- After a driver update: boot into Safe Mode and roll back or clean-install the driver. Interrupting start-up three times opens the recovery menu, where Startup Settings leads to Safe Mode.
- After changing resolution or refresh rate: Windows should revert after fifteen seconds. If it does not, start in Safe Mode and set a lower value.
- Going blank after sleep: power-cycle the monitor, try a different cable, and consider a certified DisplayPort or high-speed HDMI cable for high resolutions.
- Flickering at 4K or high refresh: an older cable may not carry the bandwidth, so a newer certified cable often cures it.
When is it the monitor, the graphics card or the board?
A simple set of results tells you where the fault sits. If a second monitor works on your PC, the first monitor or its cable is at fault. If no monitor works and the PC runs, the fault is the card, RAM, CPU or board. If integrated graphics work but the card does not, replace the card.
A standalone monitor that has failed is often cheaper to replace than to repair, but a board, memory or graphics fault is worth proper diagnosis. Xigox's indicative price list shows 8 GB RAM from ₹1,499 to ₹2,499, and motherboard repair from ₹2,999 to ₹8,999. See desktop motherboard repair for the board-level side.
Frequently asked questions
Why does the monitor say "No signal" while the PC fans spin?
The PC is powered but not sending a picture. Check the cable is in the graphics card's port, then reseat RAM and the card, since a failed start-up test also produces no signal.
Can bad RAM cause no display?
Yes, it is one of the most common causes. Without working memory the PC cannot finish its start-up test, so it never reaches the stage where it sends a picture.
My new graphics card gives no display. What now?
Check the cable is in the new card, its power cables are fully inserted, and the card is seated. An older BIOS or an underpowered supply can also stop a new card from starting.
Does clearing the CMOS delete my files?
No. It resets BIOS settings such as the clock and boot order, not your data on the drive.
Is a blank screen a sign my data is lost?
Usually not. A display fault does not touch the storage drive, and your files remain intact while you fix the problem.
If you have been through these steps and the screen is still blank, Xigox can collect the PC, diagnose the fault and give a written quote before any work begins. The ₹350 inspection fee is refunded if you go ahead. See the computer no display fix page, check the price list, or book a free pickup.
