If this is a desktop PC this is usually the point where I would give it a clean and just ensure all cables are seated securely, and to remove and reseat RAM, and if it's much older to consider refreshing the heatsink paste.
At the very least, were it to recur I would have already removed all of the most likely causes of it and it would aid better debugging.
Additionally... time to download the motherboard manual if you have not and to figure out what POST LEDs exist on the board.
If this is a desktop PC this is usually the point where I would give it a clean and just ensure all cables are seated securely, and to remove and reseat RAM, and if it's much older to consider refreshing the heatsink paste.
At the very least, were it to recur I would have already removed all of the most likely causes of it and it would aid better debugging.
Additionally... time to download the motherboard manual if you have not and to figure out what POST LEDs exist on the board.