Few important points to check when a computer fails to start:

1. Please check whether the power cable is properly plugged in the power socket and the mains switched on.

2. There are many cables coming into the CPU and going out and connecting elsewhere. Please check whether all the cables fit snugly into the sockets provided. Some connectors need nine pin, sixteen pin or twenty five pin connectors as the case may be. In certain cases when the cables are mishandled one of the pins are broken and when you use such cables the computer will not start. So make sure that all the pins of the connectors are intact.

3. Usually power to the computer is drawn through an UPS. A battery of an UPS has a life of 1000 cycles and after 1000 cycles (one charge and one discharge of the battery constitutes one cycle or in other words if you switch on and off the UPS one cycle is completed) it has to be replaced; otherwise the power supply fluctuates resulting in the failure of the CPU.

4. The display unit or the monitor of a computer may be checked whether it is switched on. Sometimes we switch it off and forget it. So the next time we switch on the computer the display doesn’t show. Make it a habit to switch off the display unit at the time of shutting down and switch it on at the time of starting the computer.

This is a check list which will help you many of the problems associated with a blank screen or non-booting of the computer.