How do psu's kill?

[LIQUIDHERION]

I have an asrock mobo cinema geforce videocard and audigy 2 sound.
I bought a used psu for 25 bucks and thought nothing of it. The brand is Axio Technology and i checked thier website and they seem as normal as the next guy. Since then i've lost 3 hard drives and 1 optical ( but the optical was crap anyways)
So how is it that psu's kill? i can only figure its from the psu sending varying voltages to the hard drive and "shorting" it to death.
I've checked my voltages and they are such:
VcoreA - 1.66
+3.3 - 3.31
+5 - 4.54
+12 - 10.60
-5 - 1.29- 1.44
-12- -0.18 -0.24
+5vsb 4.82
+vbat 3.23

Its the -5 and -12 that change the most. I've read the post here and am looking at the forton psu as my next psu.
How does one "catch" a bad psu before it strikes your components? power supply tester or is there another way. thanks.

[kemist]

man that psu is crap, get rid of it already. Do yourself a favor and stop killing your harddrives

[uOpt]

The voltages reported don't kill harddrives, unless they head-crash from being underpowered.

What a piece of junk. If the volts reported are accurate.

[WeStSiDePLaYa]

those numbers are useless unless they are from a multimeter.

other than that, those numbers are within the atx limits.

except for the 12v rail which is out of spec by .2v

assuming the reading is from a DMM.

if not get one and check.

[LIQUIDHERION]

yeah i threw it out the axiom psu. Im shopping for a enermax or fortron. I'll be sure to look for quality from now on. Thanks everyone