A Little knowledge can Kill
Most of these Techs are paid Peanuts for what they do, and the ones who know what they are doing are bored out of their sculls doing it, and thus resort to scouring customers PC's for Pron and the like (there was a story on this a few months back).
Something like a Bad RAM stick is a rare thing, I agree, I have only personally seen it once in the 10 years I have been working in IT, but it still should be something they can diagnose. There will either be
a.) a beep code (if any of these techs actually knew what that ment)
b.) a bios error stating that the memory is non-existant
c.) if the system powers on and doesn't do anything, and they HDD is powered up so by process of elimination it is one of 3 possible components as the PSU and HDD are known good.
-Motherboard
-RAM
-Video
and one of the first things any tech should have learned is the process of replacing suspected bad with known good.
These "Geeks" do nothing but give real IT Professionals (notice that we do not refer to ourselves as "Geeks") a bad name.
I cringe every time I see a Nerd-mobile or a Geeksquad car pull up outside someones home. I want to call the police every time it happens because I know they are about to be robbed.