I have a hp desktop about 5 years old..few days ago we had a power outage. power came on and off a few times ..i wasnt home but my pc was on when i came home my pc was off and wouldnt start..i try to push...
> bad power supply
Try an ordinary lamp in the wall-socket -- to make sure that a circuit-breaker inside your home has not "tripped", i.e., no power to anything that plugs in.
If there is an on/off switch beside where the power-cord connects to the power-supply, switch it to the "off" ("zero") position.
Unplug the AC cord from the power-supply.
While watching the fan inside the power-supply, and/or watching the fan on top of the CPU, plug-in the AC cord. One of the fans may "twitch", if there is power.
Flip that rocker-switch to the "on" ("one") position, and see if one of the fans "twitches".
Also, look on the motherboard for a small lamp -- it may go on if the AC power-cord is connected,
or may go on when that "back" switch is set to "on".
Try a different power-supply. If still nothing, then it's your motherboard that got "fried".