Dell Optilpex 755 DT Power Supply Upgrade

As you know, the issue you are going to run in to is that your Dell uses a proprietary PSU. You have a couple of options:

1. Try to find a Dell 755 Minitower case to move your guts into and then use a larger Dell or "standard" PSU.

2. Try to install a standard PSU in your current case. It looks possible, but is difficult to determine without measuring the PSU's dimensions (length, width, height).

3. You could also remove your optical drive (DVD-RW or whatever you have) and install a VGA PSU like this one (http://www.newegg.com/Product/Product.aspx?Item=N82E168...). This would require you to use an external optical drive.

Last, you can also look at a website like txcesssurplus.com to see if there is another, stronger Dell PSU similar in size to the one you have now that could work.

Good luck!