990 FXA UD3 - Not Starting Up?! :S

[iiRISH_LUcK]

Hi there!

Today I recieved my new Gigabyte 990 FXA UD3, put everything together in my NZXT Phantom.

Previously, I had an nVidia card, but when I bought the new mobo, I bought a new 6950 and sold my gtx 460


Everything's hooked up, and I press the power button, and the 'power led' turn's on for a split second, then off, and nothing boots.


Please help


SPECS:

Gig. 990FXA UD3
XFX 6950
2 x 2GB Kingston 1666MHz Memory
550W Powercool PSU
Coolermaster V8
NZXT Phantom
500GB SATA II WD HDD

[Dark Mantis]

Hi

Make sure that you have connected up all the power cables, ie the 24 pin and 8 pin to the mohterboard and the two connector blocks to the GPU as well.

If all that is ok check for shorts to the chassis.

[iiRISH_LUcK]

Hi

Make sure that you have connected up all the power cables, ie the 24 pin and 8 pin to the mohterboard and the two connector blocks to the GPU as well.

If all that is ok check for shorts to the chassis.

Yes, everything is connected.

Could it be the PSU?

an what could cause a short?



Thanks

[Tiger]

The Powercool 550W 12 volt amperage rating is very low  compared to other 550W models. You may want to use a power supply certified by AMD for the HD 6950.

GTX 460 models:
Minimum of a 450 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 24 Amps.)
Two available 6-pin PCI-E power dongles

AMD Radeon™ HD 6950 System Requirements
■500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended

Powercool 550W
+12V1 13AMPS 
+12V2  14AMPS

[iiRISH_LUcK]

In the 990fxa UD3 manual it say's about the system will be 'unbootable' if the PSU voltage is too low. 'We recommend a PSU greater of 500W'

That could be what's wrong.



I contacted gigabyte to see if that's what could be wrong.  Now just awaiting their reply.

[Dark Mantis]

I think that Tiger has a good point there and it could very well be the PSU. I missed the fact that it was so low powered.

[iiRISH_LUcK]

I think that Tiger has a good point there and it could very well be the PSU. I missed the fact that it was so low powered.

That's also the only think I can thing off.  It mentioned in the manual that 500W is minium, so this cheap powercool psu is probably below that.

I didn't want to buy a brand new PSU, just bought this motherboard, new case, new graphics card, G700 mouse, G510 keyboard and g930 headset.  Though I spent allot, I wanted to keep it as low as possible.

I've learnt my leasson. Spend a little more next time   Will order new PSU tomorrow.

[Dark Mantis]

Make sure that you buy a good quality one from the likes of Corsair, Enermax, Seasonic, Gigabyte etc. Also try and get one with a single 12v rail if possible as they will be more flexible in their approach to large loads. I would suggest a size of about 650W as a good alround unit.

[iiRISH_LUcK]

Make sure that you buy a good quality one from the likes of Corsair, Enermax, Seasonic, Gigabyte etc. Also try and get one with a single 12v rail if possible as they will be more flexible in their approach to large loads. I would suggest a size of about 650W as a good alround unit.

This is what I was thinking of getting: http://www.ebay.co.uk/itm/Corsair-Enthusiast-TX850-V2-850W-80-PC-Power-Supply-PSU-/140529960597?pt=UK_Computing_PowerSupplies_EH&hash=item20b83d0695

850W Corsair - Reason for 850W is I will Xfire in the future

[absic]

Yes, that Corsair PSU should do you well.

I am actually running a Corsair PSU in my own rig and have been very impressed by its consistency, despite the abuse I have put the poor thing through! 

[iiRISH_LUcK]

lol That's good to hear!  People have been slating Corsair since they moved factories, but they still give the 5 year warranty which obviously says Corsair have faith in it.  Corsair has always impressed be.

Hopefully I will get this psu ordered tomorrow.  Worried though about spending £100, and not fixing the problem.    

[absic]

You'd be surprised at just how many problems are actually down to the PSU and I always build new PC's from the PSU up.

If you can't "borrow" a different PSU to test your motherboard with you are in a difficult position but the only thing I can say is, if it doesn't resolve the problem, you know you'll have a damn good Power Supply!

As a matter of interest what CPU are you running as I can't see that mentioned anywhere?

[iiRISH_LUcK]

Sorry, I forgot to mention

Currently I'm using - AMD X4 955 Black Edition @ 3.4GHz

[Dark Mantis]

As absic says that is a good PSU. I am using the HX850 in my main machine and it has put up with many things that I have thrown at it without grumbling. If you can afford the extra the HX is even better as it is modular and a slightly better build again, it even comes with a seven year warranty!!

[absic]

Although the most likely cause of the problem is the low power of your PSU, you could take the time, whilst waiting for the new one to arrive, to do as Dark Mantis has suggested and double check that you are not getting a short circuit from somewhere.

If you look through this thread: http://forum.giga-byte.co.uk/index.php/topic,5704.msg45814.html#msg45814 I explain how to test the components outside of the PC Case. This is always a useful step as you will then know if there is a problem with the basic hardware or, if everything fires up outside of the PC Case, that there is a possible short circuit when you are putting everything together inside it.

Another thing to double check is that you have connected the cables from the power and reset switches on your PC Case to the correct pins on the motherboard header.