Computer Not Turning On. In this guide we cover the most common scenarios that might be the Unfortunately it seems the issue is so frequent that we still keep getting the same questions, why is my computer not turning on, my computer failed to. The most common way that a computer "won't turn on" is when the PC actually does power on.
If the computer starts, troubleshooting is complete. Fortunately, you can get a pretty good idea by noting how and when the PC fails. Maybe the computer doesn't turn on at all, maybe it powers up but shuts right down, or maybe it blue screens.
Remove any discs and USB devices.
A computer can not turn off by itself.
Thanks. i did what you told that removing cmos battery ,that posible causing the computer not to open. This specific error refers to a PC that isn't getting any power. If the computer starts, troubleshooting is complete.