I knew a guy that went to China to work on main frame computers at large enterprises. He said the most common problem was rats inside the facilities chewing on the wires! Inside the computers!!
LOL…I traveled by steam locomotive train 2,000 miles to a remote plant near Korea. The boiler kept tripping off line. I was stumped because all the safety interlocks that would cause a trip were working fine. Then I jiggled a wire in the main control panel and it was loose. I found 80% of the wire connections were loose — maybe vibration from shipping had loosened them. I tightened every single wire termination and thatfixed the problem.