What causes a side mirror to go out?
 

My driver's side mirror would no longer angle up or down although it would go side to side. No big deal anymore, as I took it off and replaced it with a mirror from a wrecked '02 that I found in a junkyard and that mirror is the same color and working out great. I'm curious though, is this a common issue?

Well it would go side-to-side very well but up and down stopped completely. I could move the mirror up or down by hand though.

So replacing the mirror motor/internals is not easy? I didn't think it would be. I kept the old mirror (cleaned it up even) in case I ever need to fix it or even put it back on in a pinch.

no not a common issue. sometimes dirt or water gets behind the mirror and will rust the fingers/metal wire and break a segment. rare item.

Let's hope it's rare! I don't want anyone else affected and I want my replacement mirror (and passenger side mirror) to last a long time!

How would one clean out the mirror's insides?

I would not touch it, its a pain to take the auto adjust mirrors apart. ( my own opinion ) if you decide to do it make sure you get a service manual for your car.

Ugh! Well that sucks. I won't mess with it right now then. I'll also keep eyes open for more mirrors in silver color!

I can get a little crazy when it comes to "stocking up." At the moment, my passenger side mirror is working fine and I have the passenger side mirror from the wrecked car I got the replacement driver's side mirror from.