The computer will not turn on
If the computer does not turn on, first check the power supply. Please note on the monitor – if it lights up the led, then at least his power. In this case, first check the switch power supply of the computer (behind BP). If it's disabled, enable it and recheck the PC. New off to speak about the presence of a short circuit. In this case, disconnect all peripherals, including the mouse with the keyboard. Then turn on PC – if download go, look for a short in the periphery. The mouse and keyboard you can check replacement.
Many motherboard have a power indicator led. Removing the side panel from the system unit, it is possible to see whether the led is lit. If Yes, but the PC does not turn on, it speaks about malfunction of the motherboard or other serious defects. In this case, it is recommended to seek assistance from the service center.
The computer starts but the download does not go
The cause may be a faulty component – for example, RAM, or the failure of the bootloader. On malfunction of components of the computer usually informs the tone signal, its transcript can be found online. If not loading, try to start to correct the situation by pressing when you start your PC press F8. A window will appear the menu, there you should select "last known good configuration". In most cases, the PC then successfully boots.
If you download PC has failed, you can try to recover using the installation disc. The easiest way to do Windows 7 – by running the OS installation, click restore, then select the troubleshoot problems download. After that, the computer should boot. To restore Windows XP have to manually enter some commands, a detailed description of this procedure is in the network.
To check you can try to boot computer with a Live CD included with the installation of many of the builds of Windows. If the operating system has loaded, you will be sure that the hard disk and other components are OK, the problem should be sought in the bootloader or the OS itself – for example, it can be damaged by viruses.
The fault of the video card and monitor
Sometimes the cause of the black screen is a video card failure, you can check replacement. If the PC has an integrated video card, you can connect a monitor to it. The appearance of the image definitely points to a malfunction of the primary video card.
If the computer is booted, power-on indicator of the monitor lights up but no picture, Shine a light on the screen with a flashlight – you might see a very faint image. In this situation, everyone is talking about the failure of the monitor inverter or backlight. This problem should be addressed at the service center.