Gigabyte mother (ga-ma785gmt-ud2h) not working with a GTX 750ti? No image. Help

[HelpGraf]

Greetings,

I have purchased a graphic card (MSI GTX 750 ti, pci-e 3.0), that i want to install on my motherboard (Gigabyte ga-ma785gmt-ud2h rev 1.1), the PC is starting (no beep sounds, etc.), but I don’t have any image.

A few more details:

PCI Express slot
- I’ve thought it was an issue with the pci express port, but when i’ve installed another graphic card, it was working.
- The GTX is rather long and SATA cables are partially blocking its insertion. But with a bit of pressure, the pci-e slot switch activates and it seems the card is well plugged in the slot.

Power supply
- For the power supply, it was taken from a HP computer, 300 watts. Perhaps the issue comes from this? The GTX 750 ti is known for its low consumption (around 60/75w, a model without pci connector from the PSU so all the power is derived from the pci-e slot) but it’s still 30 or 40w more than the other graphic card I’ve mentioned that is working (30w). Nonetheless, the fans of the GTX 750 ti are functioning, so it may means that the card is under tension?
- Still on the PSU, my motherboard has a 8 pin CPU connector while my PSU has a 4 pin one. Perhaps it’s related? (not enough power and stability delivered to the motherboard?)

BIOS
- My motherboard bios version is the F10 Beta, perhaps I should return to the F9 version?
- Perhaps there’s an option to set in the bios as well?
- Maybe an issue with pci-e 3.0 cards (as the motherboard is pci-e 2.0)?

The graphic card
- It’s brand new, well protected in its package during the shipment, and no sign of burns or damage on it.

Thanks in advance for your help

[Vezina]

The power supply seems fishy to me.The 8 pin CPU power connector is also needed.It really depends on how the mobo slot is fed with power(via ATX or  via the 8 pin one).

Get a Corsair power supply of 450W or more as it should have all the needed connectors and power.

A 2-nd issue could be incompatibility between the PCI-E 3.0 video card and the PCI-E 2.0 motheboard slot.Depending on the BIOS-es of the mobo and video card they may not get along together in spite of the fact that they should.
Test the card in another PC.You could ask both vendors support teams to see if they should work.

Also make sure you insert the monitor in the right video output You will not see image from the 750 if you insert the inputs in the on-board.
The on-board should be switched off automatically.

[HelpGraf]

Thanks for your answer,

But do you think that the dozen of watts of difference in consumption between my Radeon X1650 and my GTX 750 ti can explain why my computer boot with the first, and doesn't display anything with the second ?

I would prefer not to buy a brand new PSU if the issue isn't coming from it. But i don't have any other means to test the GTX :/

For the support team, yes i've reached out to both, the one for the graphic card recommends a 400w PSU.

[dmdilks]

I have to agree with Vezina about the PSU. The GeForce GTX 750ti - 20A and a 400W PSU minimum. The card is using all the amps from the PSU.

You are lucky you are getting the computer to boot at all. Does the PSU have a 2 - 6 pin plugs for the video card or are you using adapter plugs?  The card needs 2 - 6 pin plugs.

[HelpGraf]

Well, it was indeed because of a weak PSU that it wasn't working. I've bought a new one, more powerful, and the GTX 750 ti is now working.

Now i have some issues with my HDD recognized every other boot by my motherboard, i will certainly create another thread about it.

Thanks for your help  

[Vezina]

Anytime !