You have to be careful with PSU issues, because if it's dying or spiking it could very well corrupt everything in your system as a whole. It could be underpowered, if the mobo light comes on and is getting power, but nothing else can the PSU could be losing power slowly, or just be acting up which you have to be careful of because it may act the "wrong way" one day and blow something up =/
Honestly the only way to try is by testing out another PSU. Also make sure your connections are seated properly on the mobo for the 24pin and 4pin connectors fro mthe power supply, double check the cables, make sure nothing looks exposed and perhaps corroded by any chance. Checking the obvious physical issues is usually overlooked and could sometimes solve the problem. Maybe try a different outlet too for your PC, could be something to do outside the machine itself. Always a possibility, but to know for sure whether it's the PSU or not I would try another cheap PSU in its place for a few days and see what happens. First though, check al lthose connections and maybe replug everything in to its corresponding socket.
AMD 3400+ 2.4GHz
1GB DDR Crucial RAM