Hey guys my first time  posting on this forum and was hoping someone could help me out. I have an Evga nforce 680i SLI motherboard with 8 GB of ram and  a core 2 quad CPU. Whenever I turned it on it would go through the POST operation fine until recently. Now whenever I boot up the computer the on board LED  shows two dashes (--) on it. I checked the forums around here and other places as well and it had come to my attention that it could be one of two things. 
1. faulty motherboard. 
2. faulty PSU 
I cant test my PSU since I don't have an extra computer to test it on and well if it's a faulty motherboard then I guess my only option is to either RMA it or get a new one but if anyone knows what should be or can be done to test one of these option and advise on what my other options should be that would be much appreciated. 

you can try the paper clip method

Hey guys thanks for the quick response its much appreciated. @Devildoll after I do the paper clip test what should I be looking for? Is there anything subtle that I need to keep an eye out when I do this

what the paperclip does is to fake the on-signal that the motherboard is supposed to send when you turn on your pc ,
 if the psu fan and every other fan connected to the psu starts spinning , the psu is fine.