Computer won't turn on when Graphics card properly connected

[digitalmiget]

Hi,

I just put the following build together:

Intel i5-3550
AsRock Z77-Extreme4-M
MSI R7870 Twin FrozrIII OC
G.Skill-NT 8GB Kit (4Gx2)
ASUS PCE-N15 Wireless-N Network card
Samsung SATA 22x Black DVD RW
Seagate 3.5” Barracuda 1TB
Thermaltake Dokker (Case)
Thermaltake LitePower 600Watt PSU

The R7870 has two sets of 6-pin sockets which I only connected one set initially.

The pc booted up fine (all fans working on CPU and graphics card etc) and I installed all the drivers. The win7 system, however, failed to recognise the graphics card. I checked the ASROCK setup and PCI Express is the default for the boot graphic adapter priority.

I checked on the various forums etc and with the manual and realised I needed to connect both sets of 6-pin connectors to the graphics card, which I did. When I rebooted, the monitor remained blank even though the pc appeared to have power and boot up to some extent with the HDD and Power lights on as it "booted" up with fans working.

I changed monitor and connected it thru the hdmi ports on the motherboard and graphics card with the same result.

When I removed one of the 6-pin connectors the pc rebooted ok but the graphics card was again not recognised.

Searching the forums I believe it could be the PSU, but it is 600W and with only the above in the case I am surprised it is struggling. The MSI starter guide requires 500W+. The psu is also incredibly quiet in operation.

I do not have access to another pc to check the graphics card.

Any help as to the cause of this problem would be gratefully received.

Cheers

 

[clarkjd]

It still could be your PSU. Thermaltake is not known for their PSU quality.

If you remove the graphics card completely, can you boot from the internal graphics?

 

[digitalmiget]

It still could be your PSU. Thermaltake is not known for their PSU quality.

If you remove the graphics card completely, can you boot from the internal graphics?

yeh i can still boot from the internal graphics

 

[digitalmiget]

If it is the PSU's fault i might replace it with the 'Corsair VS650', any thoughts on it, is it good enough for the build. I will be using the computer for gaming a lot.

 

[clarkjd]

If it is the PSU's fault i might replace it with the 'Corsair VS650', any thoughts on it, is it good enough for the build. I will be using the computer for gaming a lot.

At this point, I would tend to suspect the PSU, however it could be the graphics card itself. You could RMA the card, and if it still wouldn't work, then replacing the PSU would be in order. The Corsair PSU would be a good one for a single graphics card. If you anticipate going crossfire in the future, I would bump up the wattage to 700-750, just to have some headroom.

 

[digitalmiget]

Thanks for the response i'll try and replace the power supply today.

 

[digitalmiget]

Best answer selected by digitalmiget.