Its either your overclock settings, undervolt settings, or your risers are bad or your PSU is dying/cheap.
Could be anything really.
Too bad your rig freezes and halts. Most crashes usually cause a system reboot and you can auto-restart the mining but not when it hangs like this.
I already tried running the miner without undervolting and overclocking. Still got the same issue. My PSU is brand new. The rig is only less than two weeks.