A while ago, I dedicated about 5 hours(not including the special sleeving using some tubes which took about 2 hours), making my computer absolutely PERFECT. About 2 days after that, PSU died on my, the PSU I took 2 hours to sleeve has died, had to basically undo the 5 hours of work. Got pretty ****ed off, gave up on the whole thing (left my sidepanels opened) until yesterday. Just put the side panels back on and install the new PSU that i got from Lazerman.
Didn't take my time to make the cables nice, expirienced ALOT of overheating. Got about a 6 degrees increase in CPU idle temp (from around 32C to 38C)and the case temp increased by 2-3 degrees. My video card overheated, and it just went all crazy.
Cable management is really important, especially if you use fan cooling.