So, SparkFun tech support periodically (about once a month) has customers contact us about their Arduino Pro or Pro Mini failing after a year or so of use. What I typically advise is something along the lines of resetting the fuse bits:
thinking maybe the fuse bits can get changed (without touching them through the ISP) after some extensive use?
I figure this is at best a partial answer that may only work for some and not for others. Some people say the resonator can fail, but I don’t entirely buy that.
Any information on what kind of lifespan people have been able to get out of their Arduino Pro or if fuse bits can magically flip is appreciated. Unless it is obnoxious information, in which case it will be ignored
stevech:
Of course, the Vcc must be within spec, and the current in or out of an I/O pin, or the sum of all, must be within specs.
That's what I usually chalk the issue up to. But people claiming their fuse bits are bad after extensive use happens frequently enough that I got suspicious and though I would check. Maybe if the digital rail is held just slightly too high for too long fuse bits can get forgetful or something like that. Or possibly too much current from one of the I/O pins for too long.
I also figured if the resonator was the issue the resonator wouldn’t start oscillating, stop oscillating, then start again, as it happens for some people.
I have seen weird behavior if the brownout detector wasn’t set - mainly EEPROM or flash corruption. I guess the fuses may get wiped out the same way. Nowdays, I always enable the BOD.
