Most of my house is lit by ceiling-mounted triple spotlights which use 40W R50 bulbs. Recently, three bulbs in the same position in one particular fitting have blown within a short time of being fitted. One lasted about thirty minutes, one almost three hours, the third survived into the next day. I've checked as much of the unit as I could without wholesale disassembly and found nothing obviously wrong.
All three bulbs came from a DIY shed multi-pack. Though it seems unlikely, is it possible that there was something faulty about a whole batch of them? Failing that, what else could cause this problem?
Many thanks, and a happy and healthy new year to one and all.