I traded my cousin some really expensive RAM that I happened accross for his old desktop, that he put his graphics card into that he swapped from his newer computer. If I plug the desktop into the wall and try to turn it on nothing happens. If I open it up I can see that the where the wire from the power supply plugs into the motherboard there Is a little light on. So clearly some power is getting somewhere…
How do I go about trouble shooting this, and what tools do I need? I assume at minimum a multi meter? Not really sure what to do, it’s been decades the last time I built a computer.
I do think it’s a good idea to do what you did and just try it as is, since there’s actually a pretty decent chance that it just works.
However, if it doesn’t work, i would check everything as if i’m building the PC from scratch. Are the parts compatible (good old pcpartpicker is here for that), is the PSU sufficient, is everything plugged in the way the manuals say, etc