??? What MB and what CPU and what RAM??
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Incorrect vs not compatable are two different things.
Most ram when first installed will default to the Standard for that type of System.
Example using DDR3 which comes in three flavors, 1.35V, 1.5 V (standard) and overclock Ram (ie 1.6 V and 1.65V) Note standared refers to the specification.
Ex: if you put DDR3-1600 cl7 @ 1.6 V into a system, when you first power up it will normally default to 1333 speed @ 1.5 V (Listed as SPD)and you have to manually change it to the 1600 @ 1.6V Which is listed as XMP profile x. This is a compatability issue, NOT incorrect RAM.
Incorrect Ram would be putting DDR2 into a DDR3 system and Vs versa - Don't think it is possible with out excess force as size or slot is different.
Two Possible conditions to distroy your MB/CPU.
(1) The memory was defective and created (A) overvoltage to CPU memory controller or (B) it shorted out the MB supply voltage.
(2) This requires changing the voltage from the default to a Higher value (ie DDR3 from 1.5 -> 1.65 ). For older systems like I5-760 1.65 should not be a problem as long as the memory is spec'ed to run at the higher Voltage, BUT the newer I5-2500k has a spec (from Intel) of 1.575V so it is possible (Small) that runing the Ram @ 1.65 V could damage the CPU which in turn could damage the MB.
Another possibility along these line is using 1.35 V Ram and some older MB defaults to 1.5 V. Although the RAM should handle 1.5 OK there is again a small possibilty that running 1.5 V on 1.35 V Ram could cause it to malfunction and then take out the CPU/MB.