The initial symptoms are in line with the BAD CAPS (see google) plague. For that you do the inspection and replace those boards.
For months I have been having that problem, I turn on my PC and I hear this sound I have attached as a zip file. and the PC would not boot. then I would fiddle with the memory and video card making show they are in tight and then it would boot normal, but after some time of using the PC I would sometimes get a blue screen saying dumping and after the dump I would have to restart. or I would just get countless restart. I would have to power off the PS from the switch for a few hrs or over night and the power back on the the restarting would stop.
I also use and Antec EarthWatt 500 and I get the same problem, but a few days ago I noticed that my Antec was making a hissing sound, like it is leaking electricity, but the pc would stay on, until I start to play video games for a while or MAA on Facebook. the hissing would stop after a while but when something gets too hot, the PC would just restart, and keep restarting until I turn the power on from the back of the PS for a few hrs or over night and then it would start again.
I tried cleaning the PC, PS, Video Car and Memory like I normally do every 6-8months and now the pc would not start. I just keep getting the Long beep, or is it a Long and 2 very short beeps, you tell me after you have listened to the audio file. I have tried fiddling with the VC and MS to no avail. I tried unplugging the Dvi from the card and I would not get no beeps at all, pc would just stay on. plug monitor back and no beeps. power off PS and turn it back on, I get the long beep again.
PS. most times when I get the Long Beep the fan on the Video Card spins really fast, like hyper fast. You can also listen to the file here https://youtu.be/sZCN2sQymGo