Unlike previously posted here, the MSI DKA790GX Platinum is NOT compatible with the Mugen2. As seen on
http://global.msi.com.tw/index.php?f...1&prod_no=1552 there is a heatsink on the motherboard next the to CPU socket. The fins around this heatsink are in the way of the lower left heatpipe of the Mugen2.
There is a way to make it fit: the fins are connected with a small copper connector linking each fin the previous one. This connector can be loosened at one end. Either bending this connector away or cutting it off completely will allow the fin to move a bit. It is possible to install the Mugen2 this way, the heatpipe will push two fins aside a bit but it is not a problem. The installation is a little tricky because you will probably have the motherboard upside down so you can't see what's going on with the fins.
The backplate can be mounted, but it will sit against the pushpin of the same cooler. This does not pose a problem but it is something you should be aware of.
Note that cutting or bending the part on the motherboard WILL void the warranty, so do it on your own risk.