I found a person asking this question over yahoo answer, how to turn on computer without using power button?
As an IT Engineer, I use this method since 5 year ago when I learn how to assemble computer on my 1st job. Most people sure curious how to turn on computer if without power button? This is not hard, as long you have some technical knowledge over motherboard, and able to identified the power switch location.
Please bare in mind, do not test this if you do not have any basic technical knowledge, or consult some professional before you do it.
Most of the motherboard have a sticker like above, the PC assembler have to stick this sticker behind the CPU casing, you can found this sticker around the CPU casing. This sticker indicate the location of the power switch.
Power button, Reset button, Hard Disk LED , Power LED on the casing all are connected to this section. Most people found that their power button spoil, or broken, they will have difficulties to turn on their computer.
See the above picture, power switch (SW), reset switch (SW) and etc, all this are connected to the motherboard from the power button, reset button over the casing. When you see closer to the switch (SW) you can see it connect into the motherboard, the SW will insert and connect to 2 metal pin in the motherboard.
In the easy way to describe, when you press the power button, this 2 pin will be electrically connected to each other, and send the motherboard a signal to power on the system.
To start the computer without using the power button, take out the “Power SW”, make sure you identify which 2 pin belong to the power button (refer to the labeb behind), use a test pen or any metal surface to touch the two pin, it won’t have any electrick spark, just allow the electrict signal from 1 pin sed to another pin, your computer will be start without pressing any power button.