Z68X-UD7-B3 problems powering on

[CJM1682]

so this is my 12th pc build, and my first problem.. i have the following specs below:

G.SKILL Ripjaws X Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-14900CL9D-8GBXL
Intel Core i5-2500K Sandy Bridge 3.3GHz (3.7GHz Turbo Boost) 4 x 256KB L2 Cache 6MB L3 Cache LGA 1155 95W Quad-Core Desktop Processor BX80623I52500K
2 x crossfire - SAPPHIRE 100314-2SR Radeon HD 6870 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity
GIGABYTE GA-Z68X-UD7-B3 LGA 1155 Intel Z68 SATA 6Gb/s USB 3.0 ATX Intel Motherboard

i am using a 900watt power supply which has been tested in another system to work.

upon hooking up the power supply to the motherboard the appropriate LED light up in the Power button as well as the red ones towards the bottom of the board indicating that it is receiving power. when the power button is pushed the fans begin to spin than stop instantly and the LED's in the M1 indicate:

green - M1
orange - M2

the system will not power up under any circumstances please help! it is useless to invest into a system that wont work!!

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

Firstly remove all hardware that isn't required for bootup.

Next make sure that you have all power connections to the motherboard firmly made. That is the 24 pin connection and the 8 pin connection.

Next  remove all memory modules apart from DDR3_1

Make sure that you have a buzzer attached to the motherboard's spkr connection.

Pres the power button to boot.

Post back with the results.

[CJM1682]

okay the mobo has been removed from the case to to eliminate shorts, i have removed the processor and resat it to verify a good connection all the power cables are disconnected and only 1 stick of RAM remains in slot 1, i have alternated the the stick between the 4 i have to troubleshoot if it is a bad stick and all cards are removed to only the CPU and a stick of RAM are connected all the power cables have been reconnected to the board to ensure they are all on all the way. the problem persists. the mobo book states a yellow LED in md2 means overvoltage???

[Dark Mantis]

I would suggest that you try a different PSU as it would seem possible that it is faulty. Make sure that you use a good make like Seasonic, Gigabyte, Corsair, Enermax, Coolermaster or Thermaltake to name a few. Also make sure that it is at least 800w minimum preferably with a single 12v rail. Anything less than this will probably not be powerful enough to run your system successfully.

[CJM1682]

i have new developments. i have added components 1 by 1 with successfull power-ons untill i add the gpu to pciex16_1. once i add the card i do not get a successfull boot, but it will boot if i dont have the power cables connected to the card, this also makes me think PSU is that your thought still?? looks like i will have to go out to best buy or something and over pay to get this up tonight if thats the case.

[CJM1682]

well now i am nervous i dont want to buy a PSU if i dont have to. i did something rather unconventional and powered on the board with the gpu in the pcie slot without the 2x 6pin power connected when it held power successfully i plugged the 2 6pins in with the board still on i know rather dangerous with power spikes but i am out of options the board stayed on at this point and booted to my windows OS. but the problem remains that if i shut down or power off i cannot get it to power on with the power connected to the GPU. and in some cases with the GPU even in the slot. please help as no local stores carry a power supply over 850 and if my current 900 watt isn't enough for 16GB ram 1 HDD and 2 GPU's than wtf!!

[Dark Mantis]

Well that would back up my thinking that it could well be the PSU that is causing the problems. Just don't get some cheapie thing just because you are in a hurry to get it fixed as it could go down and take a lot of your expensive hardware with it.

Your update would go along with what I have just said too. It is quite poossible that the PSU just can't take the strain of the starting current for everything at once but by doing your unconventional startup you spread the load over a lentgh of time and it managed to hold up. The startup current is always the greatest  as once running everything uses a little less.

It's not that your PSU isn't powerful enough just duff!

[CJM1682]

so should i look for 1 with certain amp ratings on rails?? because now its not even starting with the GPU uninstalled, i just have a hard time beliving that a 900W psu that works in my other system also wouldn't be able to keep up with this boards start-up with only a CPU and 1cpu fan aswell as 1 stick of memory connected.


p.s. i just dont want to shell out another $150 only to find it doesn't fix the problem either.

[CJM1682]

I will go pick this up now if u think it will help will this be sufficient to use/test with?

Thermaltake - 850-Watt TR2 RX Power Supply - Black
Model: W0319RU

[Dark Mantis]

I have just done a search of the net and they don't seem to have a particularly good rating. Apparently they tend to not last too long.