If you are only looking for the manual to figure out where to plug in your Power Button or Reset Switch, most ASUS boards from the "N13219 era" use a standard 20-pin . Power LED: Usually the top left 2 or 3 pins.

Look for a printed string near the PCI Express slots or between the CPU and RAM. It will look like P5KPL-AM , M2N-MX , or P5GC-MX .

If you're unable to find the manual, you can also try contacting ASUS support directly or checking websites that host user manuals, such as ManualsLib or ManualsOnline.