Building new PC, wont boot. Power shuts off

[bubba J]

I just put together a new computer. The power comes on, CPU fan and case fans run and then all power just shuts down after about 10 seconds. I never get anything on the monitor and no beeps from MB. Tried unpluging HD and CD drives. Using ECS N2U400-A MB with AMD 2500 and 512 kingston value ram. Any thoughts ? Thanks

[Paleo Pete]

First thing to try is a bare bones boot outside the case on a non-conductive surface. You'll need motherboard, CPU, RAM, video card and keyboard. Nothing else. You may have to remove the power supply from the case, sometimes you can stand the case on it's side and the power cables will reach.

Short the power on jumper, all it takes is a second, if it powers up, you have a ground problem. Something is shorting between the motherboard and the chassis.

Make sure the CPU is correctly installed and thermal compound is REQUIRED. AMD chips come with thermal tape, it should be adequate, most of our regulars prefer Artic Silver. Swapping to Artic Silver will void your warranty, consider that before using it. If using Artic Silver or other thermal paste, use a small amount, spread it into a thin layer and install the heatsink.

Also make sure video card and RAM are correctly installed and fully seated. While testing try to connect a speaker so you will hear any beep codes.

Once you get that far, if you still have no POST, let us know.

[bubba J]

ok I tried the bare bones boot outside the case on a non-conductive surface. I still get the same results. When the power is turned on, the keyboad lights flash, the CPU fan starts, and then after 5 seconds all power just stops. I dont get any beeps from the speaker I attached. I did not use thermal paste, just the film that came on the CPU. I guess I will go get another Power Supply to rule that out first.

[John0904]

Originally posted by Paleo Pete
Make sure the CPU is correctly installed and thermal compound is REQUIRED.

Pretty sure this is the problem. CPU is over heating and the motherboard is shutting down as a prevention.
Triple check the heatsink and make sure is it firmly clipped on the CPU.
And as Pete said, have some kind of compound between the CPU and heatsink.

If it is 100% secure, there might two other problems that come to mind.
1. You have a short some place.
2. A faulty device. Either the CPU and or motherboard.

[ski]

Also, make sure that the CPU fan is connected to the correct MB terminal.
If it is and the MB's CPU fan terminal has 3 pins, then make sure that the CPU fan's connector also has 3 pins(2 are for power, 1 is a sensor that detects that the CPU fan is running. If the CPU fan fails, then the entire system shuts down to prevent the CPU from overheating and getting damaged).

[bubba J]

Ok, I tried a different Power Supply and it does the same thing. CPU fan and MB have 3 wires and only goes one way. Tried reseating CPU and mounted heatsink again and have the same issue. Only thing I have not tried is the thermal compound. The docs that came with the AMD CPU state that the warranty is voided if I use any thermal compound. It has a gray compound attached to the bottom of the heatsink. When I remove the heatsink, there is an impression where it is making contact. Thanks for everyone's advice.

[ski]

Make sure that the CPU fan is connected to the correct MB fan terminal.
Sometimes there's more than 1 terminal in the same general area.

If that's ok, then make sure that the CPU fan's sensor wire(usually yellow) is ok at both ends.

If ok, then see if resetting CMOS with a MB jumper works.

Also, make sure that the heatsink is correctly mounted, and that it's not hanging up on anything.