Bad caps

Well, seems that we aren't immune to bad caps either. No real surprise there, though.

Taking picture of the bulge is often tricky but just trust me here, once you actually see them the bulge is very obvious. Diagnosing first units wasn't exactly easy as unlike ones here the caps aren't always visibly bulged. To make things even more annoying the failure mode varied a lot; device suddenly turns itself off, fails to start on morning, starts counting distance at a wild pace, display behaves erratically... When first such device comes up, finding the real culprit may be difficult, especially since power rails sometimes seem good when measuring them on the desk, even after some gentle persuasion with heater and/or cold spray. ESR of caps very likely is off, but measuring that with caps still on board may be tricky and I don't have ESR meter handy anyway.

On the other hand, these are from devices over ten years old that have been powered essentially 24/7 the entire time. I'd say that few failures after over 80k hours of operation is within acceptable limits.

And yes, I still repair these units if asked to.