Power cables , Test your cables guys

I bought a bunch of power cables for my system a year ago and 1 day found my sub off unplugged and plugged back in was fine for a while , sub goes out again now I suspect something up so I took some measurements and low and behold my cord was giving me 85 volts not 123 like at the wall so I sent back to audio quest to replace , audioquest  honestly not feeling there quality , I pulled all my cables out to put on a meter . Just because you spent allot on a cable measure it anyway ,  I wish I would have . I hope it didnt damage my pb16 being under voltage like it was for a year , SVS says They don’t think so , but I know low voltage can destroy certain appliances or even create a fire .   What other tests can we do to measure our interconnects just to be sure we don’t have a defect , after happening to me I’m checking all points I can as far as power goes and I urge everyone to check cause it can happen .