Computer Turns On But There's Nothing On The Screen

What you're actually seeing

The power button works. You hear fans. Maybe a light on the front comes on. But the screen never shows anything — no logo, no spinning circle, sometimes a message like "No signal" floating around. That is good news in one small way: the computer is getting power. Something between the computer and your eyes is not working.

• The monitor says "No signal" or "Check cable" and then goes to sleep.
• The screen is completely black with no message at all.
• You see the manufacturer logo for a second and then nothing.
• The screen flickers on and then goes dark again.

The short answer

About half the time this is the monitor, the cable, or the wrong input selected. The other half it is inside the computer — memory that has worked loose, a graphics card that has failed, or a motherboard fault. The checks below sort one from the other in a few minutes without opening anything.

Safe things you can check

1. 1

   Check the monitor has power

   There should be a light on the monitor itself. If there is no light at all, the monitor is the problem, not the computer.

2. 2

   Press the monitor's input button

   Monitors with more than one socket can sit on the wrong input. Cycle through HDMI, DisplayPort and VGA and give each one a few seconds.

3. 3

   Reseat both ends of the video cable

   Unplug it from the monitor and from the computer, then push both ends firmly back in. Loose cables are extremely common.

4. 4

   Try a different cable, or a TV

   Any HDMI cable and any TV will do as a test. If a picture appears on the TV, your monitor or cable is the fault.

5. 5

   On a desktop, check which socket you're using

   If the computer has a graphics card, the cable must go into the card's sockets — usually lower down on the back — not the ones built into the motherboard.

6. 6

   Listen and watch the computer

   Fans that spin up loudly and stay loud, beeping, or a light that blinks in a pattern all mean something and are worth telling us about.

What not to do

• Don't keep pressing the power button over and over. It won't help and a hard shutdown mid-startup can damage files.
• Don't open the power supply. There is nothing user-serviceable inside and it can hold a dangerous charge even unplugged.
• Don't start pulling parts out of a desktop unless you're comfortable doing it and the machine is unplugged.
• Don't buy a graphics card, memory or a new monitor on a guess. Replacing the wrong part is the most expensive way to find out what was actually wrong.

When it's inside the computer

If the monitor works on another device and the cable is good, the fault is in the machine. The usual causes we find on the bench are memory that has lost contact in its slot, a failed graphics card, a power supply that can start the fans but not hold a proper load, or a motherboard fault. On laptops it is more often the screen, the cable that runs through the hinge, or the backlight.

What about your files?

Repair or replace?

It depends entirely on what failed and how old the machine is. A stick of memory or a cable is a small job. A failed graphics card in an eight-year-old office desktop may cost more than the machine is worth, and we'll say so. A diagnosis tells you which conversation you're having before you spend anything.

When to bring it to us

If the monitor and cable check out and the screen is still black, bring the computer to Affordable Computer Repair in Bellevue. Bring the power cable with it — for a desktop, the tower on its own is enough, you can leave the monitor at home unless you think the monitor is the problem. Consultations at our counter are free, and we'll tell you plainly what we find.