I've got near DOAs (failed within hours, maybe never worked right) from MSI and Gigabyte. one Abit warantee crossship came with a busted digital audio port (NB fan failure). I've also got a DOA cheap graphics card from Biostar.
so for me its about 1 in 3 for mobos and vid cards.
once I get a good on it can be dismanted and reassembled several times, so its not just me busting them.
there, that should scare off any noob considering a build.
thats why you try stuff before doing it all up nice any pretty.
never had a dead or failure with CPUs or HDDs
had cheap PSUs go, not good ones. never catostoficly. even then its still usable, but extremely unstable/noisy. so I had warnings.
Had a wireless keyboard die after just a couple of months, and a CRT monitor in 2 years way back in the day.