Is the new board requires a different number or placement for standoffs. Pull the motherboard and remove all standoffs that don't match your new board.
Also, check the board for jumper settings. Some come with the CMOS clear jumped, etc.
Second most common is a power plug unplugged. See the ATX 12V noted in the product manual.
So I've recently fried my motherboard on my gaming pc by plugging in a fan while it was powered on (I know stupid mistake). I've went to the nearest computer store near me (MicroCenter) and picked up a new msi H110M PRO-VD motherboard because they assumed that's all was the problem. I returned home and put everything back together expecting a power up and nothing happened. I've checked her power supply and that's working as well but with everything plugged up I have no clue. Any idea if it could be something other than the power supply and the motherboard causing my pc to not start up at all? Thanks.