|If this is for a laptop or netbook computer, the power switch has to be one that is made to be used with your laptop or netbook model. Consult a local laptop repair place, |
If this is for a desktop computer, the power switches used for desktop computers are extremely reliable.
I've never encountered a desktop computer that actually has a defective power switch.
Almost always, when someone thinks there's a problem with the power switch it's actually caused by something else
Sometimes the case button that presses on the power switch sticks inward such that the power switch is always on - make sure that's not stuck.
If that case button sticks inward such that the power switch is always on when you press it to boot the computer, the mboard will shut off in about 4 seconds as if you held in (or held down) the power switch.
If it's still stuck inwards when you attempt to press it again, the computer won't boot - the case button must be un-stuck before pressing the button will boot the computer, unless you remove the AC power to the computer and then restore it, in which case the mboard will boot but will shut off in about 4 seconds if the button was still stuck in.
If your computer has a generic case, if it has a button for a Reset switch, it's the same type of switch as the power switch on modern ATX computers - momentary contact - it's on only when it's pressed The Reset switch's wiring connector(s) can be connected to the pins on the mboard for the power switch, and visa versa.
Other than that, for a desktop computer, the power switch not always working can be due to
- , the female connector(s) for it's two wires are too loose on the pins on the mboard it connects to
- you are having other problems, caused by.......
- a power supply that is in the process of failing
- a power supply that has insufficient capacity to handle the amperage draw of a video card you have installed in a slot on the mboard
- a problem with your mboard - e.g. failing electrolytic capacitors
- a poor connection of wiring connections or of components to the mboard - e.g. a poor connection of the ram to it's slot(s)