Something was "causing his computer to not work." What does "not work" mean? Details on the computer model, hardware, OS, and the specifics of the original problem are lacking.
It may not even be hardware.
I usually look for software reasons before cracking open the case. A lack of proper drivers, viruses, spyware are pretty common causes these days.
Let me try to explain the situation first.
My friend gave me his computer to check the RAM and processor to see if they were causing his computer to not work. So he brought it to my house and gave it to me overnight.
I first took out the Video Card so that I could easily get to the RAM and set it aside.
I then took out the RAM from my computer and realized the one was a CL3 that he had given me so I couldnt check because my motherboard supported CL2.
So my next step was to check the processor. I had put in the POSSIBLE bad one and put back the cooler and heatsink.
When I turned on the computer I would get a "no signal" from monitor, or a "going to sleep". I kept tryin to reconnect the video card and tried another monitor etc. but same problem...
So I then put the original processor back in and the same problem occured. Now my friend is upset and I am left with asking for help.