> > I might think twice about doing a board that was fragile with age, but > otherwise, change 'em all. Like replacing both headlight bulbs if one > goes out--it's just a matter of time before the other one goes.
Do you seriously replace both headlight bulbs when one fails? I know of nobody who does that. Generally you carry a spare bulb kit and a screwdriver and if a bulb fails, pull over and change it. Why not change all other bulbs on the car at the same time? Or change them all once a year as part of the service [1]? What about bulbs in your house? [1] OK, this is done for things like lighthouse bulbs which are replaced after so many hours of operation, but that is a rather different case. -tony