Hi Adrian,
You might be on to something there, and provide a possible reason why cables and/or connectors might just fail while being plugged in, as mentioned by Martin.
Yes, a dry joint will produce an intermittent and time dependant fault: initially sound with no manifest problem, but becoming either noisy or completely failing with time. That is one of the reasons why, where possible, I like to assemble my own interconnects. That way I have complete control on the choice of cable and of connector, as well as the neatness and quality of the soldering.
Until recently, my system used a concatination of components each with their own connector style. Thus I had to make up leads fitted with a variety of connectors: RCA phono; DIN; 1/4" jack; XLR; Teuchel, and CAMAC as interconnects. As my system moved towards one where most of the components used balanced-line connections, for the sake of expediency and convenience, I would often buy ready made leads from respected cable companies such as Studiospares and Chord etc.
One set of balanced-line cables I used between the preamp and a buffer amplifier are made by Chord. In the past I have tried out some un-balanced Chord coaxial cables, terminated with RCA phono plugs and loaned to me on a try and return basis - and have to say I was most unimpressed with the quality of their construction; in fact I had to repair them in order to use them. It is quite possible that the Chord balanced cables were poorly soldered and had a dry joint. In reassembling the system I replaced the Chord cables with some using Mogami 2549 cable and Neutrik XLRs, as the latter were shorter, and I like to keep all cable lengths to a practical minimum.
I will inspect the soldering on the Chord cables carefully - it might explain what happened.
Thanks
Barry