Funny and dumb question, but is there any way to determine if a CPU is dead/burn by only inspecting it ? ( without attaching it to a MoBo and power it on ).
If the CPU has massive damage, you can see if it has any burn marks on the PCB or any melted solder points. If there is minor damage, you probably won't see any damage.
Other than that, there isn't really much you can do to tell if it is non functioning without powering it up.