No way for us to know remotely.
Hard crash without BSOD can often be a serious hardware problem. The first thing I would check is the PSU. Is it powerful enough to power the system? The next step would be to contact the motherboard manufacturer and do troubleshooting with them. They will walk you through finding the problem because they don't want to RMA the board. If they tell you it's a different component then contact that manufacturer and so on. You might have to RMA something along the way.