PSU Problem - cause of psu dying?

[Ayer]

For the past couple of months I had a problem with my computer. When I played more demanding games sometimes my computer would turn off as if it was lacking power. Sometimes I could play games for hours and nothing would happen but sometimes my computer would turn off at the loading screen of the game. I checked and this was definitely not a temperature problem so I thought that it might have been a bad psu. Yesterday there was a small "explosion", the computer turned off and the psu smells which means that it has burnt out I guess. So my question is why did this happen? Why did my psu die/burn out? I only had it for about 3 years, I used my computer for about 8-10 hours every day. My cpu is an i7-4790K, my gpu is a GTX 770 and my power supply was a Corsair CX750.
In the past I also had a lot of problems with my power supplies and a lot of my power supplies would die/burn out and I never understood why this could be happening.

 

[Ryan_78]

Well that explosion or anything was due to poor quality of the PSU. The corsair CX PSUs are very low quality and are likely to malfunction or explode. Those are tier 4 PSUs according to PSU tier list and are low quality only suited to business. Not gaming. Also because it is low quality, and since it is used for a high power gaming rig, it will wear out the PSU extra quickly. Replace with a good tier 1 PSU. Also using extra hours daily wil require more wattage and wear it out
List http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html