Chips get dirty too, how do you clean them once you have released them from the CPU Socket?
Hold the CPU chips like this, try only touch the sides not the top and bottom of the chip.
Needs a bath.... just wipe it with some tissue paper.
Rotate in small circles till it is clean. Avoid touching the bottom you will put oil and moisture from your skin it causes rust.
Intel Celeron G3950
-M.M.-