Is it normal for the computer's power light to blink?
On a desktop computer, there are two lights: one for power and another indicating storage device (hard disk drive or solid-state drive) activity. The following sections go over each type and whether or not it is normal for these lights to blink.
Power light
Normally, the light on or surrounding the computer's power button has a solid, consistent glow. However, if the computer is in sleep or standby mode, it is normal for this LED (light-emitting diode) to flash or blink. The light blinks to let you know the computer is still on but is in a power-saving mode. If your computer is in one of these states, pressing any keyboard key or mouse button should exit and bring you to the computer's lock screen.
My computer is on and the power button is blinking
Sometimes, the power light can blink while the computer is fully active if someone mistakenly plugs the Power LED connector into the HDD LED connector on the system panel connector. As a result, the power button blinks when the computer's primary storage device performs any read or write action. To fix this issue, ensure the ends of your power leads surround the appropriate headers on your motherboard.
Another reason the power button may blink while the computer is on is because of a power supply problem. For example, if you recently installed a new video card, it may be using more current than your PSU (Power Supply Unit) can provide when it's under heavy load. Ensure your power supply's wattage is adequate for your computer's total draw.
Hard drive light
Most computers have a hard drive indicator that flashes each time the computer's storage device reads or writes data. As you use your computer, this light alternates between flashing and staying solid for a few seconds. This behavior is completely normal.