Lost power

My PC was fine but I bought a new case fan which I connected to my motherboard. While I was playing a game, my pc lost power unexpectedly and started to turn on and off repeatedly. I switched it off, unplugged my power cable, disconnected the fan and drained the power by holding the power button...

I have recently went through many sites to try and upgrade my motherboard which is a retailer mobo (ASUS) but there seems that there aren't many big brand mobos around, or if they are, they're really expensive. Are they becoming obsolete or it it just a temporary thing? If they are obsolete...