|"Should i try to replace parts or just give up and get a new pc?"|
How about investing in a good power supply instead? You should expect to pay about $75 US for a decent quality name brand 650W PSU. How much did the Sumvision 600W cost, $25? When it comes to PSUs, you generally get what you pay for. Here's a clip from a review of the Sumvision 500W:
"... Once we increased the load to 75 per cent, the PSU ran for five seconds before exploding spectacularly. The Power X is very cheap but can't even deliver 375W, let alone 500W. One to avoid."
Maybe this will help you take make a better decision: