Computer does not start

PC users often complain that their system unit is not turning on, without telling the details of the problem. Most often it turns out that we are talking about the impossibility of loading the operating system, and not about problems with turning the PC on. When your computer does not boot because of operating system or BIOS errors, it is necessary to search for a solution to a particular problem. However, it is quite possible that you are facing the situation when your computer really does not turn on – that is, its boot does not even begin or immediately ceases, before the software comes into operation. Causes of such a situation are not so much, and below we will tell you about the main ones.

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Table of contents:
1. Your computer does not respond to the on/off button 
2. Your computer starts and turns off immediately 
3. Your pc turns on, but the monitor does not work

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YOUR COMPUTER DOES NOT RESPOND TO THE ON/OFF BUTTON

In most cases, the problem that is causing troubles with turning your PC on is quite trivial – the lack of electricity.

So first of all you have to make sure that the system unit (or laptop) is connected to a power source. Inspect the wire connected to the computer power supply unit for any mechanical damage, and make sure that the connector itself is not physically damaged.

If the power supply cable is fine, you need to start diagnosing the outlet to which your computer is connected. Try connecting another electrical appliance to it and make sure that it is in operating order.

All modern power supplies have an On/Off button right on the case, and this button interrupts the power supply when necessary. It is important to make sure that the button is in the “On” position.

Important note: On some power units there is also a button with a switch for various voltages (most often 220 volts and 127 volts). Such a switch is not performed in the form of a button, and for transferring it to another mode it is necessary to use some tools. If your regular voltage is 220, and the switch is in the wrong mode, you must turn it to the right one.

When the power supply and the power source are checked, you need to make sure that everything inside your computer is connected correctly. It is also important to check that the front panel is connected without errors otherwise the power button will not be able to operate as it is supposed to.

Please note: In many modern cases, the power button has an indicator that confirms its correct connection and indicates by its glow that the computer is connected to the electricity and there are no problems with this.

YOUR COMPUTER STARTS AND TURNS OFF IMMEDIATELY

There is a situation where after you are pressing the power button your computer starts to boot, but it turns off before the audio notification that indicates checking the hardware for errors (“peep” at power on). This problem may occur for the following reasons:

• Graphics card malfunction. If the computer has both – an integrated (built into a CPU chip) and a discrete (separate) graphic cards the problem may arise due to the hardware conflict. To check this, you need to disconnect a discrete graphics card from your computer, connect the monitor to the connector from the integrated graphic card and try turning your computer back on. If the computer turns on without a discrete graphic card, you need to check it for contact contamination and physical damage. In addition, the problem may be related to the improperly selected power supply unit.
• Burnt motherboard. Motherboard is one of the most complex PC components. If it fails, your computer will refuse to turn on. You can determine that the motherboard is burnt by the capacitors soldered on it. If they are swollen, you will need to repair or replace the motherboard.
• CPU overheating. Another common reason for your computer to shut down directly after it starts to boot is a CPU overheating. When the CPU is not receiving any cold air from the cooler (or the cooler is not efficient enough), the chip may overheat in just a few seconds. In such a situation, you need to make sure that the cooler is correctly connected to the CPU. Also, the processor will quickly overheat if the thermal paste is applied incorrectly.

Note that in some cases, your computer will let you know which of its parts have problems with the characteristic beep. For example, in case there is a rapid CPU overheating, the system unit starts to “squeak,” and if there are problems with the graphic card, it may make several long squeaks when trying to boot. Depending on the BIOS version, the information transmitted by the “squeaks” of your computer when it is turned on will vary.

YOUR PC TURNS ON, BUT THE MONITOR DOES NOT WORK

If the system unit turns on (coolers rotate and the lights indicate that it is working), but the monitor is not displaying any images, you first of all will have to check the cable connecting your monitor to the system unit. You may also want try switching the cable from a discrete graphics card to an integrated one in the CPU.

If your computer turns on, but the monitor does not work, and this problem is not related to the graphics card, you need to check the following:

• RAM serviceability. To do this, take all RAM slots out and try to start your computer with each one of them separately. Before installing RAM into the motherboard it is recommended to wipe the contacts with a soft rubber removing the possible dirt and fingerprints.
• Correct operation of the motherboard battery. As you know, the motherboard has a battery, which is necessary so that not all information was unloaded from memory when the computer is turned off. It is recommended to get it out for 10-20 minutes, and then install it back again and try starting the computer. If previously there were symptoms of its malfunctioning (for example, resetting the time and date), you should try replacing the power supply.
• Power supply. If the power is insufficient for the operation of all PC parts, some of them may start working (for example, coolers will spin), but the monitor will not display information on the system boot. It is necessary to make sure that the power supply is selected correctly, and if it is not you will need to disconnect one of the energy-intensive PC parts or install a more powerful power supply.

Much less often computer does not turn on or image is not displayed on the monitor because of an error when connecting a USB device. It is recommended to disconnect all USB-devices from the computer at boot.