Another update: Just while standing besides rig, It went tick that kind of noise like a power on sound and all cards stopped working.
Not sure from the thread if you've solved this or not but if not that tick sounds like it could be PSU related. I had an underpowered rig and the PSU would definitely click when it maxed out. Are you running all the rigs off the same circuit? The instability across multiple rigs could be because of overloading?