Here are some ways to check the make and model of your motherboard:
1. Look at the computer case (back, side or top) - the make and model will be listed somewhere in plain sight. Now check the manufacturer's site for complete specs for your computer, including the motherboard model. (Of course you will need a working computer in order to do this).
2. Open up your computer case. Look for a label/tag on the motherboard. This label/tag will state the model and serial number of your motherboard.
3. Take the motherboard out of the case and examine it. This will definitely give you the make and model number of the motherboard. Serial number too.
4. Make a personal visit to a computer store and describe your situation. In many instances, they will be able to help. I have done this by emailing digital pics of the inside of my computer, and then visiting the sore and discussing what I was looking for.
The way to check for a dead motherboard is to assemble it in a different case and then try to power it up. Very involved procedure.