GA-H55N-USB3 Won't Power On

[smburns25]

I just built a new system. See specs
GA-H55n-USB3
G.Skill Ripjaws (2 x 2 GB)
Silverstone SG05 Case with 450W PS
Shuriken CPU Cooler
Crucial 64 GB SSD

No cards or GPU installed as I am planning on using HDMI on MB.

I assembled everything (this about my 10th system build).  Plugged in the system and pressed the power switch.   The power light comes on for a second, the PS fan and the CPU fan spin for about a second and I get a yellow internal light that flashed on for a second.  That's about it.  The yellow light will flash a few times at about once every 4-5 seconds and nothing happens.  No post.

Any ideas??  I sounds like a MB short to me as this happened on a ASUS board I built last year.

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

I would tend to agree that it does indeed sound like a power problem of some kind. Quite possibly a short to the chassis. The best thing, once you have checked that you have inserted all the power cables properly, is to remove the motherboard form the case along with the CPU/heatsink/fan, memory, buzzer and PSU and test it on a cardboard box.

[smburns25]

Not a short to the chassis.  I have the MB (no CPU, Fan or memory installed) on a box connected to the power supply and I get the exact same response.

If this is a bad board, then I need to order one today as a replacement.  Any other thoughts?

[Dark Mantis]

OK. Have you inserted the 24 pin and 8 pin power cables into the motherboard connectors ?

Nothing is going to happen without the CPU installed anyway!
Put in the CPU/heatsink/fan and memory.

What slots have you got the memory in ?

What beep code does the buzzer make ?

[smburns25]

There are only two slots for the memory on this board and I am using both.  With the CPU, memory, and CPU fan installed and the PS plugged in to the board, I get no beeps or sounds of any kind.  The PS fan and the CPU fan turn on for a second.  The three lights on the MB turn on (red, yellow, green) for about a second and then everything shuts off.  The power on/off cycle repeats a few times and then the board goes off completely.

[Dark Mantis]

It sounds lioke you have some major problem there then.

It would be worth checking for bent pins on the CPU socket also.

Very carefully remove the heatsink and fan. Probably a slight twisting motion is best to release the two as the thermal paste can act like a glue.

Once off remove the CPU taking extreme care both physically and electrically(static) and place somewhere safe.

Make sure that the lighting is very good and even.

Now scrutinise the socket for any pins that are out of alignment, even slightly.
If in any doubt whatsoever take a couple of macro (close up) photos of the socket and post them on here for us to check.

Also look at the bottom of the CPU at the lands (little copper circles) and make sure that there is a mark in each somewhere near the centre.
If there are any missing marks or any of the pins are obviously bent then that is your problem.

Before refitting the CPU clean off all residue of the old thermal paste and the same on the heatsink and then apply a small amount (about the size of a grain of rice) to the centre of the CPU once it is inserted in the socket.