Lenovo Case, Nvidia GPU, and PSU Compatibilty

[Nixon720]

It's been a 2 years for me with the Lenovo Thinkcentre E73 Mini Tower Model and I've recently been considering upgrading my GPU. My original configuration are of the following specifications:
i5-4440S 2.80GHz
6 GB RAM
Nvidia Zotac GT 610
Default 180W Lenovo PSU (which came when I bought the setup as a whole)
And the rest miscellaneous components like HDD and such..

So recently, I bought an Nvidia GTX 960 4GB without considering the other involved factors. Upon further searching, I found that the PSU must be atleast of 450W to comfortably run the given configuration with a replacement of the GT 610 with the GTX 960. When I went to the tech shops, they told me that the Lenovo Thinkcentre case is such that you need to get a PSU from a Lenovo Supplier itself and that no other regular options would fit in the case (such as Corsair/Silverstone/Thermaltake/etc). Another tech said that said regular PSUs would have different screw threads that wouldn't allow the PSU to screwed into place, if you managed to get the PSU to fit in the first place.
My question is whether these proposed issues are true, as I am skeptical that they are. Also, please let me know further solutions apart from buying a new case. Thanks

 

[pete_101]

Yeah, they most likely are true. Also, a standard ATX motherboard take a 24 pin power connector and Lenovo often use a 14 pin connector instead. So even if you do find a way to fit the PSU in, you need an adaptor between the PSU and the motherboard. Search Youtube and you'll see it's true, many videos there of people changing the connectors over.

The lesson here is, do your research before buying or better yet, build your own.