Many years ago I was a systems programmer for a Burroughs B6700 mainframe in New Zealand - this was the only mainframe at the University, everyone depended on i

Many years ago I was a systems programmer for a Burroughs B6700 mainframe in New Zealand - this was the only mainframe at the University, everyone depended on it for almost everything. One day it started doing random IOs to random devices - garbage on a printer or a console were annoying, but scribbling over disk was a particularly bad thing, we could be down for ages bringing it back. We had an engineering contract with Burroughs and eventually they flew in the big gun engineer from the US ..... He took a stick and ran it down one row of cards in the IO processor, nothing happened, he ran it down the next row, bang! hours later we're up again, he runs it down half the row, bang! binary search with stick ensues, eventually he starts pulling cards one comes out and 3 small solder blobs fall off, they'd been sitting there on some chip's pins since it was manufactured years ago