The computer turns on but no display

It’s great to have a powerful computer on which games fly, 20 browser tabs open without hesitation, and the SSD pleases with the speed of operation. If the display refuses to please with a picture at one not-so-beautiful moment, the system manager’s power will not be helpful.

Why does my computer turn on but the screen is black?

When the system unit or display does not turn on, expensive repairs will not be needed. Most often, this happens for a banal reason: there is no power or some minor breakdown. Maybe the electricity was turned off, or the socket broke.

However, the option with a power outage does not suit us because we assume that the system engineer has earned money, the cooler has started spinning, but the monitor does not show signs of life. In this case, the algorithm of actions begins with the fact that it is necessary to reject the most obvious reasons and then proceed to diagnosis. You will likely have to look under cover of the PC case.

The monitor does not work: what to do first?

Modern displays delight with their durability. Many serve for 10 years or more without repair. Therefore, if the old monitor does not work, do not rush to panic. The absence of a picture on the screen does not mean the display is broken. Maybe the reason is the computer or the cable.

Power check

A banal reason why the monitor does not turn on is accidentally pressing the device’s power button while it is idle. This can happen, for example, when dusting. After some time, the user turns on the computer and sees a black screen. The problem is solved in the most elementary way – by pressing the display’s power button. 

Check the cables

If the cable is not equipped with additional fixing elements, it tends to fall off the connected device. In the case of a monitor, it is necessary first to provide a signal from the computer. If a VGA or DVI cable is used, it must be fixed on both sides with screws. If the cord has come off, fix it properly.

The monitor does not turn on when starting the computer: what else to check?

If it was impossible to solve the problem at once, let’s proceed to a deeper analysis of the situation. You can start by locating the fault.

Check the monitor, cable, and system controller separately. To do this, you need to turn off everything, disconnect it from the computer and connect it to power. If a message appears on the screen that the cable is not connected, there is no signal, etc., this is a good sign. But if the LED of the monitor is lit, it is not a guarantee of performance at all.

Due to a damaged cable, breathe easy: buying a new one will not be a problem. It is more challenging to deal with the display and the system controller. If the monitor is broken, the latch may be in the power supply unit. In this case, you may have to send the display to the service.

Power Supply

Of course, we will not discuss the computer’s PSU but the node responsible for powering the monitor. When the display does not turn on, repairers often mistake it, and it turns out right. 

Repair of the built-in PSU includes the following stages:

  • If there is a fuse on the board, check it first.
  • Visual inspection of capacitors. Drinking those that are swollen and replacing them with new ones.

Repairing the built-in PSU makes sense if you know how to read circuit diagrams and work with a soldering iron. There is only one option – to take the monitor to the service. PSUs are usually not repaired: in case of breakage, they are replaced with a new one.

Video card

If the monitor does not turn on when starting the computer after installing or replacing a discrete video card, the power adapter may not have enough power. Developers have written on their sites the minimum requirements for computer PSUs. If it says, for example, 850 W, and you have a 600 W PSU, the adapter naturally does not have to start. Another cause of problems is improper installation of the device: it was not inserted into the slot, it was not connected to the power supply, etc.

Unplug the power cable from the case. Remove static from your hands by touching the heating radiator. Remove the discrete cover from the case, and connect the monitor to the built-in one. If it worked, then the source of the problem was found. Simply switching the cable to another port is not an option. It is necessary to remove the adapter from the case. Only then will the computer understand that sending a signal to the display through the motherboard port is essential.


The operating system is a typical culprit for the lack of an image on display. Especially if the computer has several memory sticks, the user added a new die, tried to overclock the old one, etc.

If there are several strips, it is necessary to try to start the computer, leaving only one of them – the one that was in the original configuration. It should be in the same slot it was in initially. If it did not help, we continued the search for the trouble source.

We disconnect everything without which the computer can boot: we remove the cables from the USB ports, and we remove the network, audio jack, modem, tuner, etc., from the case. In general, all boards are without which the system starts. We disconnect the hard disk.

Turn on the computer. Did the picture appear? Perfectly. We turn off the PC and connect the disconnected devices one by one. If the signal stops coming to the monitor at some stage, the culprit is most likely the part that was attached last.

If there are more than two memory slots on the motherboard, it is necessary to follow the layout of the bars. An unpleasant situation is possible when the user, trying to “start” the monitor, rearranges them incorrectly, although the reason was not in the RAM. As a result, instead of one problem, two have to be solved.

RAM or video card contacts

There is one more factor that should be taken into account in the search for an answer to the question: what to do if my computer turns on, but the screen is black? The signal on the screen may appear after cleaning the contacts of the RAM or video card. The contact surfaces of both components must be periodically adjusted. If the PC is old, paying attention to them at least once every six months will not hurt.

A simple procedure allows you to eliminate the oxidized layer, which prevents complete contact between the board and the slot. It is logical to do this after cleaning the “underhood space” from dust. It makes no sense to insert clean contacts into a dusty slot. First, we vacuum, then we rub the boards.

In conclusion, it is worth mentioning the BIOS reset option. If you configured something in it, the monitor stopped working and returned the values ​​​​of the parameters that were there before. Can’t restore settings from memory? Reset the BIOS to factory settings. Remove the power battery and insert it back after 5 minutes.