Problem with a built pc

[Jdog1218]

So I was trying to help a friend out by helping build his pc one component at a time. He bought a prebuilt system (Acer TC-780-ACK15) originally and put a graphics card in it. Now he wants to upgrade the motherboard not the cpu. So He got a new motherboard but for a 8th gen system not 7th gen (didnt notice until we had the problem). I told him to do his research but he missed the part about the chip set being very much different. Well anyways me being dumb i put the I3-7400 in a 8th gen Chipset motherboard. Put it together and i turn it on then for two seconds then turns off. So I was thinking, "is the board not compatible" and low and behold it isn't. So we put it all back together with the old motherboard. Now its doing the exact same thing in the old motherboard. Did we break the cpu by doing this? Please any comments would help.

[KhakiHat]

You could trying taking out the ram and bios battery(doing so while the machine completely disconnected from a power source). After they have both been removed, try reinstalling them. Some times those two things hold onto a sort of memory. 

 

Not saying it'll 100% work, but it's worth a try.

[nick name]

I haven't heard of anyone breaking a CPU in that manner.