Random Technical Question about External Hard Drives

[hony]

I had two external drives fail on me on the same day a few weeks back. These are the external backup devices which I have on a rotation schedule via the bank vault. Never worked out why but I suspect bad earthing on the power supply as later I found the plug for the power supply was loose. I don't know much EE but I remember reading that two devices connected together which have differing ground voltages can be a problem.

Back off topic -- did any of you actually *USE* COBOL? I wrote a lot of lines of that at my first few jobs -- and yes it is very much still around, "ObjectCOBOL" was the last one I wrote in professionally!