The 24 pin motherboard connection on micro-atx, atx, and extended atx motherboards are identical due to the international standards that were adopted years ago. Any atx power supply with a 24 pin conector or 20+4 pin connector can be used with any atx motherboard. My backup motherboard is a micro-atx board with a 24 pin power connector. I connect it to a Corsair atx power supply. No problem!
What is the brand and model of your motherboard? What is the make and model of your power supply? If you could provide that information we could better advise you.
Years ago most of the name brand off the shelf systems used proprietary components so people were forced to buy replacement and upgrade parts from them. That changed with the adoption of international standards.