HD 7750 with no video output!

[Khaleal]

Hi,

I bought a Gigabyte HD 7750 to replace an old NVIDIA GT 9400GT. But when I connect it to my PC I don't get any video output (including in the BIOS).

System specs:
The system specs:
LENOVO 3000 J200 9691
CPU: CORE 2 DUO E4600 2.4GHZ
RAM: 2X1GB Kingston DDR2 667MHZ
GPU: GIGABYTE AMD HD 7750 OC (880MHZ) PCI-E 3.0 (Previous: NVIDIA 9400GT PCIE 2.0)
MB: Intel 945GC (PCIE 1.1)
PSU: Seasonic SS-400BT ECO 400W

Notes
- The BIOS is set to PEG/PCI
- The card fully works in another computer.
- The PC POSTs and boots normally (I could hear Windows sounds)
- When I connect the monitor to the integrated graphics (while HD 7750 is still connected) I get video signal.

So whats wrong with it guys?

 

[B_S]

Is the 7750 the type with no additional power connection? If it needs an additional power connection, did you plug it in correctly?

The 7750 uses very little power. However, that is an overclocked version of the 7750. Still it shouldn't use much more power than the graphics card you had before.
The specification of the card details a minimum of 400W PSU.
You have a 400w PSU. The specification detail 360W over the 12V rail.

I don't think the PSU is the problem.

Edited below:

[strike]PCIe 3 cards are compatible with PCIe 1.1 so that is not the problem. [/strike]

[strike]That graphics card is not compatible with PCIe 1.1[/strike]

You're PC has PCIe 1.1 x16. The card you have needs PCIe 1 x16. So your PC should support your graphics card.

However other sources say that the card needs PCIe 2.0 x16 to support that graphics card. I will look for more info on this.

-http://www.overclock.net/a/the-final-answer-to-the-controversial-pcie-x16-version-compatibility

 

[Khaleal]

Is the 7750 the type with no additional power connection? If it needs an additional power connection, did you plug it in correctly?

The 7750 uses very little power. However, that is an overclocked version of the 7750. Still it shouldn't use much more power than the graphics card you had before.
The specification of the card details a minimum of 400W PSU.
You have a 400w PSU. The specification detail 360W over the 12V rail.

I don't think the PSU is the problem.

[strike]PCIe 3 cards are compatible with PCIe 1.1 so that is not the problem. [/strike]

That graphics card is not compatible with PCIe 1.1

-http://www.overclock.net/a/the-final-answer-to-the-controversial-pcie-x16-version-compatibility

It doesn't require auxiliary power so the PSU isn't an issue.
PCI Express standard specifies that any later version of PCIe be backward compatible with previous versions : http://en.wikipedia.org/wiki/PCI_Express
Also see the author's update and the comments, I've seen many guys reporting being able to run this card with their 1.0 PCIE slots.

 

[B_S]

While it is true that PCI SIG while developing PCI express slots made sure that they remain compatible with each other, it is the GRAPHIC CARD manufactures (i.e Nvidia & AMD) and the sub vendors (Saffire, Zotac, EVGA etc) that really make the difference!
We all know that the AMD Radeon HD 7000 series is extremely power efficient. Having said that it comes at a cost. This power efficiency comes due to the new electrical interface featured in PCIe v3.0 and 2.0 slots and is ABSENT in PCIe v1.1 slots. Hence they are NOT COMPATIBLE.

[strike]
-http://www.overclock.net/a/the-final-answer-to-the-controversial-pcie-x16-version-compatibility

This quote suggests that YES all PCIe are backwards compatible with the previous versions. [/strike]

[strike]But, earlier versions of PCIe were not as efficient as later version in supplying the PCIe card with power.

The 7750 draws its power from the PCIe slot. But the PCIe 1.1 slot is not as efficient as later PCIe version 2 and 3 at supplying power to the card.

The card is a PCIe 3.0 card, manufactured mostly with later PCIe versions in mind. Perhaps this is the problem?[/strike]

Edited: all PCIe are backwards compatible with the previous versions

But you said many other people have been able to run the card with PCIe 1.
So then again, maybe the above isn't actually true. And the PCIe slot can supply power to the card just fine.

Or could it be that the OC version of the card needs more power than other versions?


It might be more likely something else is wrong.

 

[B_S]

Boot up the computer with the integrated graphics.

Remove the drivers for the NVIDIA GT 9400GT.

http://www.wikihow.com/Change-a-Graphics-Card

 

[Khaleal]

While it is true that PCI SIG while developing PCI express slots made sure that they remain compatible with each other, it is the GRAPHIC CARD manufactures (i.e Nvidia & AMD) and the sub vendors (Saffire, Zotac, EVGA etc) that really make the difference!
We all know that the AMD Radeon HD 7000 series is extremely power efficient. Having said that it comes at a cost. This power efficiency comes due to the new electrical interface featured in PCIe v3.0 and 2.0 slots and is ABSENT in PCIe v1.1 slots. Hence they are NOT COMPATIBLE.

-http://www.overclock.net/a/the-final-answer-to-the-controversial-pcie-x16-version-compatibility

This quote suggests that YES all PCIe are backwards compatible with the previous versions.
But, earlier versions of PCIe were not as efficient as later version in supplying the PCIe card with power.

The 7750 draws its power from the PCIe slot. But the PCIe 1.1 slot is not as efficient as later PCIe version 2 and 3 at supplying power to the card.

The card is a PCIe 3.0 card, manufactured mostly with later PCIe versions in mind. Perhaps this is the problem?

But you said many other people have been able to run the card with PCIe 1.
So then again, maybe the above isn't actually true. And the PCIe slot can supply power to the card just fine.

Or could it be that the OC version of the card needs more power than other versions?


It might be more likely something else is wrong.

The old NVIDIA 9400GT (TDP: 50W) was also using the PCIE slot for power, and it used almost the same amount of power (TDP of HD 7750: 55W).
What the guy from the link says is totally illogical. If PCI-E has power design flaws (or any other flaws) it won't be backward compatible as the standard specifies. Also, PCIE 1.1 is the second version of PCEI so it shouldn't have such flaws..
The MB's BIOS is updated to the latest one released by Lenovo (25/10/2007) so I can't do anything with the motherboard..

 

[Khaleal]

Boot up the computer with the integrated graphics.

Remove the drivers for the NVIDIA GT 9400GT.

http://www.wikihow.com/Change-a-Graphics-Card

The issue isn't operating system/drivers related.. I don't get video output while the bios is posting..

 

[B_S]

Regarding PCIe backwards compatibility. You are right. All PCIe is backward compatible. And there is no difference in different PCIe versions in the power supply from the PCIe slots.

1."Some manufacturers do not allow the built-in graphics to be disabled or to become the
secondary display." - manual

Some forum users have apparently had success starting the system with the integrated graphics. Then removing any display drivers/or devices, including the integrated graphics, in device manager. From what I understand this was some kind of workaround.

2.PCIe port can supply 75w. But the initial power supplied to PCIe port is lower, 25w. But this is automatically set to 75W when a graphics card is detected. However perhaps some motherboards will require some kind of setup to deliver 75w. Is there any kind of setting that sounds similar to this in bios?

So in other words the x16 port can function both as a 16lane pcie for gpu or a general purpose 1 lane slot. perhaps something has to be setup manually in bios for this to function.

http://en.wikipedia.org/wiki/PCI_Express#Power

http://www.intel.la/content/www/xl/es/intelligent-systems/previous-generation/945g-945gc-chipset-brief.html

But your previous card worked without problems. Perhaps the setting could somehow have been reset when you switched cards.

Or is this the same as the PEG PCIe setting you setup in bios?

3. Can you test your old card in the same PC? Perhaps the PCIe slot somehow has been damaged?

4.Could one of the cards HDMI, DVI, VGA ports be broken?

 

[Khaleal]

Thank you for your reply.

1."Some manufacturers do not allow the built-in graphics to be disabled or to become the
secondary display." - manual

Some forum users have apparently had success starting the system with the integrated graphics. Then removing any display drivers/or devices, including the integrated graphics, in device manager. From what I understand this was some kind of workaround.

As I said, the BIOS is set to PEG/PCI which means that the PC will try first to find a dedicated GPU, and if it doesn't it'll use the integrated one...
The drivers trick is useless in my case, AGAIN, I don't get any video output while the BIOS is POSTing.. the drivers has nothing to do with that as Windows is not loaded yet at this level..

PCIe port can supply 75w. But the initial power supplied to PCIe port is lower, 25w. But this is automatically set to 75W when a graphics card is detected. However perhaps some motherboards will require some kind of setup to deliver 75w. Is there any kind of setting that sounds similar to this in bios?

So in other words the x16 port can function both as a 16lane pcie for gpu or a general purpose 1 lane slot. perhaps something has to be setup manually in bios for this to function.

No such settings.. My old card worked like a dream.. no changes were necessarily..

Can you test your old card in the same PC? Perhaps the PCIe slot somehow has been damaged?

It's working.

Could one of the cards HDMI, DVI, VGA ports be broken?

I have a D-SUB monitor (which is fully working with integrated graphics and old 9400GT).. I tested this card in my friend's system and it worked well.. he also has a D-SUB monitor and a 350W PSU.. he had no issues at all..

 

[B_S]

Apparently other people have had the problem of no video during POST and boot up. Yet the video signal has worked once windows is loaded. Presumably bacuase at that point the windows drivers have loaded. Apparently with some older Intel Chipsets, no video will be output during boot up/POST via the HDMI or DVI ports. This might have been the cause of the problem for those people. Not saying it applies to your motherboard. Just that other people have had that problem.

-http://www.overclockers.com/forums/showthread.php?t=658024

Since your other card worked though, like you've said, that shouldn't be the problem. On the other hand the OP on that link had different results with different video cards.

I don't know what's going on, just guessing.

another link on that issue: http://www.tomshardware.co.uk/forum/265741-30-intel-chipset-limitation-video-post-pcie-slot

 

[B_S]

Does the fan on the 7750 work?

 

[B_S]

Maybe what was said in that article about there being some difference in how power is transferred in PCI 1 vs PCIe 2 and 3 slots is true. Maybe some video card manufacturers skimp out on true PCIe 1 support. Atleast on one other manufacturer of the 7750 it says "PCIe 1x16 support". But on the Gigabyte site there is no mention of it having PCIe 1 support. It should have, since it's a standard. But maybe somehow it doesn't?

If you can, if you bought the card in a local store, contact your place of purchase. Tell them you bought the card to work in a PCIe 1 motherboard. It doesn't work. So you should get your money back.

Edit: Or, you can contact Gigabyte. And ask them if that graphics card is compatible with that motherboard.

 

[B_S]

A possible scenario: Your BIOS is set to PEG/PCI. The motherboard will first attempt the PCIe port. If the video card is not working properly at this point, then the motherboard automatically switches to the integrated graphics. Now the motherboard will only send video signals to the integrated graphics, and won't try the dedicated graphics card.

But maybe it's true that during initial POST, the 7750 is not getting enough power due to some limitation with the motherboard. Yet perhaps later on the PCIe port could receive the additional power that would enable the 7750 to work. But at this point the motherboard is no longer trying to use the 7750. So at this point, perhaps the 7750 is actually potentially working, yet the motherboard sends no video signal to it.

I'm just speculating. But if the above is true, and you could somehow force the signal to always go to the PCIe port, then perhaps it would work? Perhaps you can completely disable the integrated graphics, then maybe that would force the motherboard to send the signal to the PCIe port.

Just a speculation as I said. If you disable the integrated graphics, and then the 7750 still doesn't work, then you have no working video card. But you can probably find some way to reset it so the integrated graphics works again.

Since the video output will work when you switch cables to the integrated graphics, that means that the motherboard is sending the video signal to the integrated graphics. But the signal should be sent to the 7750. Perhaps the motherboard will automatically sense where the monitor is plugged in and send the video signal there? Otherwise the signal was being sent to the integrated graphics already, and then the 7750 could not possibly output a video signal since it is not receiving one.

According to your other post, the 7750's fan is working. So it kind of seems as if the 7750 is getting power, but the 7750 is not being detected as working. Or the motherboard doesn't even try to run the signal through the 7750. Or it tried, but failed, and then switched to the integrated graphics?

Since there is a PEG/PCI in BIOS, and the setting is set to the correct PEG/PCI setting. Then that would indicate that the motherboard should have no problems running a dedicated graphics card in the PCIe slot, no matter what PCIe generation that card is, as long as this card follows the rules/standards for PCIe regarding backwards compatibility.

If the article about PCIe 1 supplying power differently and less efficiently than PCIe 2+ is true, then maybe that could mean there is a potential benefit for a video card manufacturer to build its card aimed at working well with PCI 2+ while not working or having some problems when using some PCI 1 motherboards?

Or perhaps it could be the case, that earlier motherboards could not output video during post. Perhaps this could cause the motherboard to think the 7750 is not working, switching to the integrated graphics instead?

You're motherboard only has one PCIex16 slot right?

During POST, the internal speakers make sounds. This is a code to sound off if everything is ok or not. Look up what these sounds mean, and compare this to what you hear.

 

[B_S]

How to disable integrated video that might interfere with the motherboard correctly identifying and using your dedicated graphics card:

http://www.wikihow.com/Disable-Onboard-or-Integrated-Video-On-Your-Computer

 

[Khaleal]

Does the fan on the 7750 work?

Yes it works.

If you can, if you bought the card in a local store, contact your place of purchase. Tell them you bought the card to work in a PCIe 1 motherboard. It doesn't work. So you should get your money back.

Edit: Or, you can contact Gigabyte. And ask them if that graphics card is compatible with that motherboard.

I bought it from another country.. I contacted Gigabyte and told them about my issue (and mentioned the pcie 1.1 version and motherboard stuff) and they never pointed to the fact that the card isn't compatible with the motherboard.. All they said is if the card works in another system then there's nothing they can do.. They say I have to contact my system supplier (Lenovo), unfortunately, this is a discontinued model and out of warranty..

Or perhaps it could be the case, that earlier motherboards could not output video during post. Perhaps this could cause the motherboard to think the 7750 is not working, switching to the integrated graphics instead?

You're motherboard only has one PCIex16 slot right?

During POST, the internal speakers make sounds. This is a code to sound off if everything is ok or not. Look up what these sounds mean, and compare this to what you hear.

This motherboard was able to output during POST with the old 9400GT..
Yes it has one slot..
The PC makes no sounds.. It boots normally..
I found no option in the BIOS to disable integrated graphics completely.. The only option is to change priority to PCI/PEG (and other options)
Another member in another thread pointed that my motherboard is one of the early PCI-E motherboard that has compatibility issues.

 

[B_S]

"If the computer passes the POST the computer gives a single beep (with some computer BIOS manufacturers it may beep twice) as the computer starts and the computer will continue to start normally. However, if the computer fails the POST, the computer will either not beep at all or will generate a beep code, which tells the user the source of the problem." -http://www.computerhope.com/beep.htm

If your PC doesn't beep it's either something wrong, or you simple don't have internal speakers installed.
If the PC doesn't beep when you start without the 7750, then probably it's because you don't have the internal speakers.

This motherboard was able to output during POST with the old 9400GT..

But the card is different somehow from the 7750, since installed in your PC one works and the other doesn't. Yet the 7750 isn't broken.

I found no option in the BIOS to disable integrated graphics completely..

In the link it says sometimes you disable integrated graphics by turning a physical switch on the motherboard.
http://www.wikihow.com/Disable-Onboard-or-Integrated-Video-On-Your-Computer

Another member in another thread pointed that my motherboard is one of the early PCI-E motherboard that has compatibility issues.

Your monitor, cables, PSU, the 7750 everything works. So the only thing left is the motherboard. Either the motherboard is broken, or it's working as intended. If it's working as intended, and follows the PCIe standards, that means the video card is not fully backwards compatible with all PCIe versions. But I think they´re supposed to be. In that case maybe Gigabyte does have a responsibility. But I think it's probably wasted time to try to RMA etc.

 

[B_S]

If you can, connect a monitor to the VGA port of the 7750.

If you can, using PEG/PCI BIOS setting, connect one monitor to your integrated graphics, connect another monitor to the 7750. What happens during boot?

What BIOS do you have? Phoenix Award, MSI?