They just dont build them like they used to, literally. Most modern technology isnt radiation hardened, meaning that cosmic rays can do untold damage, to the delicate nanoscale transistors and capacitors that make probes function. 1970's technology, though primitive to our current technology was much more robust. This is one feeling I have for why we have not gone back to the moon, that an the funding problem and the Health and Safety Nazis.

Anything could have caused a single bit to change. An impact from a cosmic ray for example may have done it, or indeed it may well have been spontaneous, with no specific reason. And yep, there are micro meteors out there that would be dinging away on it, and in its current positioning it will soon be subjected the the ravages of interstellar space. It seems a tough little beast, and very well constructed.

Jonny

The path to good scholarship is paved with imagined patterns. - David M Raup