Motherboard Or PSU
Hello, I have an Asus M4A785-M This is a new build. I connected all my peripherals, booted, computer stayed on for less than a minute then everything shut down. POST stayed on long enough to see that everything was recognized. One by one I disconnected everything until I'm down to 1stick of Ram, 24 pin power connector and 4 pin Atx. I also tried another power supply. Same problem--System speaker gives me a normal sound on power on and gives rapid beep when I remove all Ram. When I disconnect the 4 pin ATX the CPU fan and the PSU fan have stayed on for over 24 hours. The only things left on the front panel connector is the speaker and the power on button. I'm stumped...
Hi Klark, and welcome to Tom's Hardware.
Put 1 stick on RAM (check to make sure you are using the correct RAM slot), and the Video Card in the MB. See if you can get to the splash screen and then to the BIOS setup. See if it will stay on when in the BIOS setup before booting up. If you can check the voltages on the PC Health page and the temperatures. If it still shuts down, it is probably the MB. Before sending it in for replacement, I'd check the RAM slots and the CPU socket with a magnifying glass for any bent pins.
If you tried a different PSU as noted, then consider sending it in for replacement.