There is something missing here. Something overlooked.
I assume you installed the old processor in the new board. So it can't be that the processor has unseated. Did you visually inspect the pins on the processor?
I'm going to suggest my standard no boot diagnostic. Give this a try and start with the motherboard out of the case. You are trying to see if you can get the board to light up without anything connected.
**** New System Failure Diagnostic Basic diagnostic procedure is to uninstall the entire build and start over. Some people do this out of the case by placing the motherboard on an anti-static surface. This eliminates the possibility that there is a short circuit between the motherboard and the case through the connection posts (stand-offs). A standoff in the wrong location or a sloppy job will cause a short. The Test (power off, power cord unplugged):
Now connect the power cord and turn the PC on.
- Disconnect everything externally connected except the mouse and keyboard (printers, USB devices, etc). If you are not using a wired mouse and keyboard see if you can borrow one. The wireless device is just another component you have to deal with.
- Disconnect the power and data cables from all the drives inside the computer (Hard drives, DVD/CD drives, etc).
- Remove all the cards installed in the expansion slots (PCI/PCI-e) including the video card. (Be careful handling them and place them on a non conductive surface while testing).
- Remove all the RAM sticks (same rules as above).
- The motherboard should start beeping. You should get a beep code that tells you there is no memory. This is good, it means the processor is functioning and the motherboard is good so far.
- Now add one stick of memory in Slot A1 and power on. More beeping: "no video card" beep code. This is good.
- Then add the video card and connect it to the monitor. You should get no beeping and you should see the BIOS start screens, ending with the message that there is no boot device.
- If you get no video then switch the one memory stick installed for another one and test.
- If you do get video then start adding components back, one at a time, until the system fails to boot. The last component you added is then the problem component.
I would try this without a CPU to start. The board should do nothing - no beeps - but you just want to see if it gets power. Try both boards and both power supplies.
It is a weird one.