Why does my computer monitor randomly turn off?
Several issues can cause a monitor to turn off randomly. Some of relate to the monitor while others relate to the computer. Read through the following suggestions for reasons why your monitor may be turn off by itself.
If the monitor stays on, but loses signal (e.g., power light goes from green to orange), it's an issue with the computer and not the monitor. See: Why does my computer turn off without warning?
If your computer turns off when not being used, but wakes up when pressing a button, there's nothing wrong with your monitor. It's operating according to your power management features.
One reason the monitor could shut off is because it's overheating. When a monitor overheats, it shuts off to prevent damage to the circuitry inside. Causes of overheating include dust build-up, excessive heat or humidity, or blockage of the vents that allow the heat to escape.
If the monitor is overheating, unplug the monitor and let it cool down fully before using it again. Then, if you have canned air (anti-static, for electronics), try to blow out any dust inside the monitor casing. If the computer room is very hot, cool it down by turning on a fan or the air conditioning system. Wait until the room cools down some before trying to use the monitor again.
Also, if you're using an older CRT monitor, upgrading to a newer flat-panel display resolves many heat-related issues in a hot environment.
If the power cord is not securely connected to the back of the monitor, it can cause a loss of power and turn off the monitor. Make sure the power cord is firmly in place in the back of the monitor. It's also possible that the power connector in the monitor is going bad and not receiving adequate power from the power cord. In this case, it is best to replace the monitor instead of having it repaired.
Another reason the monitor could shut off is because of a malfunction in the circuitry. There could be a short in the wiring or a circuitry failure causing the picture to go black or the monitor to shut off. In this case, there may not be much you can do other than buying a new replacement monitor. Monitors are usually not economical to have repaired since the repair cost can be more than the price of a new monitor. You could bring the monitor to a computer repair shop to have it looked at, but they're likely going to suggest having it replaced.
Video card or motherboard problem
If the monitor stays on, but you lose the video signal, it's very likely an issue with the video card or motherboard in the computer. A computer randomly shutting off can also be an issue with the computer or video card overheating or a defect with the video card.
If the video card is a known good video card or its part of the motherboard, there may be problems with the motherboard. A bulged capacitor or other failing components on the motherboard can cause a computer or monitor to shut off.