“Known-Working” Doesn’t Mean “New”
To perform parts exchanges for troubleshooting, you
need replacement parts. If you don’t have spare parts, it’s very
tempting to go to the computer store and buy some new components.
Instead, take a spare system that’s similar to the “sick” computer, make
sure that it works, and then use it for parts. Why? Just because it’s
new doesn’t mean it works.
I once replaced the air conditioning compressor on my van with a
brand-new, lifetime-warranty alternator that failed in less than a week, and six more replacements failed (all from the same batch or defective parts).
Whether it’s a cable, a video card, a monitor, or some other component,
try using a known-working item as a temporary replacement rather than
brand-new. Rather than give away, sell, or discard working
video cards, hard disks, and other components you have replaced with
faster, bigger, better upgrades, keep at least one of each item to use
as a replacement for testing purposes or a…