Being its a cold boot issue, I'd have to partially agree with betoyrm. 300 watt should be enough, but its the quality of the PSU, that may be a question. The market is flooded with $10 power supplys right now, and is growing by the day. A cheap PSU, can kill a system in a flash. (voice of experience) If you can, post the name brand of the power supply, and the output, both what it shows on the case of the psu, and what the voltages are reading in your bios under system health. (if so equiped) Cheapo Power supplys are like spending a hundred grand on a new car, then putting in the cheapest oil you can find.
Phenom II X6 1055T, Asus M4A89GTD Pro/USB3
Phenom II X4 945, Gigabyte MA785G-UD3H
Zacate E-350, MSI E350IS -E45http://classicplatforms.com