I have a custom built computer MOBO is a Gigabyte GA-78LMT-USB3. All the sudden the computer just shut down. It would no longer load anything. It would turn on for a few seconds then right back off. I replaced the PSU and it worked for a couple of days, then started the same thing would not stay on long enough to load anything, and turns off. I can not get any display out if it. I took out the Graphics card and connected it to the on board display and still nothing. I have reseated the memory cards to make sure the were properly in place. I connected a speaker onboard and just get continous long beeps. Sometimes it will stay on for about a minute and other times it would turn off as soon as I let go of the power button. It has a random amount of time it will stay on but still will not load anything. I have checked all wires to make sure the were connected correctly. I have also removed all the memory and installed one at a time to see if it would load anything, yet it still does not. I'm at a loss on this one. Can anyone help?