Help me build a damaged RIG !

We can help you build any kind of rig you can pay for. :) But, could you give us an idea of what you have in mind to do? Do you want to just replace the bad motherboard or build an entirely new rig or something in between. If you could give us an idea of what you want to do and what your budget is, we could be of more assistance.

Are you having trouble playing CS:GO with your current specs? Also what about a graphics card? I don't see one listed.

The biggest help in most games are a graphics card. The faster the better. You could build a very good gaming rig for $1500.

Price this out, just as a starting point. I don't think there is a game this won't play at the highest settings.

Core i7-6700K
ASUS Maximus VIII Hero
8Gb DDR4-2400
EVGA NEX750G Power Supply
Corsair Obsidian 750D
Corsair H105 CPU Cooler
GTX 1070 or 1080

That comes out to around $1450 W/1070 FE without shopping around. You can do well still going a little cheaper, just substitute a few parts. An i5 CPU will save you about $100, for example.

I'm not really an AMD guy, but I can take a look and see what I can find. As for a cheap GFX card, I would hold on for a little while. The Nvidia 1080/1070 are going to be out, next week, I think. That will make most of the other cards drop in price pretty good. So wait a little while, if you can and see what prices settle at. if you can't wait, we can find you something.

See if this would work for you ASRock 970 Extreme4 AM3s USB 3.0 ATX AMD Motherboard with UEFI BIOS - Newegg.com

It's going to hard finding you a mid grade GPU because of your power supply. This one is a low to mid range card and is recomending a 450W PSU which is pushing yours real hard XFX Core Edition Radeon R7 250X DirectX 11.2 R7-250X-CNJ4 2GB 128-Bit GDDR5 PCI Express 3.0 CrossFireX Support Video Card - Newegg.com