No video with AMD Radeon HD6950

[bradl]

Hi all.

I'm rather stumped here, as I believe I've gone through everything, but still am coming up empty on why I am not getting any video to show up from my Radeon 6950. Some background:

I was running Windows 7 on the following:
Gigabyte GA-MA790X-UD4P ATX board
AMD Athlon Phenom II X3 945
Seagate 200GB 7200RPM SATA III HD
Western Digital 1.5TB 5900RPM SATA III HD
Seagate 320GB 5900RPM SATA III HD
Corsair XMS2 8GB (4 x 2GB) DDR2 PC6400 Memory
Sapphire Radeon HD6950 2GB (unlocked to HD6970)
Antec TruPower Blue 750W PSU
Dell 1901FP Monitor (DVI)
Dell 2009SW Monitor (HDMI)

I'm tired of towers, and after building the 2012 CustoMac Mini, I've decided to build one last machine, then I am done. So I scrapped all of the above, keeping the above PSU, Video card, Monitors, and 1.5TB drive (all my personal files and Flightsim data). With that, I have:

Bitfenix Prodigy mITX case
Gigabyte Z77N-WIFI Socket 1155 mini-ITX motherboard
Intel Core i5-3570K CPU
Corsair Vengeance 8GB (2 x 4GB) DDR3 1600 Low Profile Memory
OCZ Vertex 4 128GB Sata III SSD (I know, I'm playing with fire here, but it's working)
Hitachi 750GB 7200RPM SATA III HD
Western Digital 1.5TB 5900RPM SATA III HD
Antec TruPower Blue 750W PSU
Sapphire Radeon HD6950 2GB PCIE x16 Video card
LG 48x DVD+-RW SATA III drive

BIOS revision on the Z77N-WIFI board is F2 (latest stable).

I have Windows 7 Enterprise installed without a problem, using the onboard HD4000 video that is on the 3570K. That isn't a problem. After getting Windows installed, I've installed the latest Catalyst drivers from AMD, restarted the machine, went into the BIOS, and made sure that the following was set:

VT-d is DISABLED (wasn't listed as a setting in the BIOS, as the CPU doesn't support it)
Intel Virtualization is DISABLED
Init Display First is set to PEG
Internal Graphics is set to DISABLED
Internal Graphics Standby Mode is set to DISABLED
Internal Graphics Deep Sleep Mode is set to DISABLED

I saved these settings to a local profile, wrote them to the BIOS, exited, then powered off the machine.

I then plugged in the HD6950, using the same cables they were in when they were in the AMD box, plugged the HDMI cable back into the card's slot, DVI cable back into the card's slot, and powered on..

No video output for the monitors, though the machine boots up into Windows. I then pulled the HDMI cable, and went straight DVI...

Again, nothing. I plug the video card back into the AMD box, it starts up. I go back to the HD4000 onboard (by clearing the CMOS, loading optimized defaults, and setting INIT Display First to IGFX, and I have video. The monitors recognize the HD6950 when the cables are plugged in, but I am just not getting any output when the machine powers on and posts.

Is there a BIOS setting I am missing? I know it has to be something simple and I'm missing it. Anybody have any ideas?

BL.

 

[Going Bald]

OK, gfx card is correctly inserted in slot, right? No problems there.

Did you connect the power cables to the gfx card? This is #1 mistake most often made causing no output to display.

 

[bradl]

OK, gfx card is correctly inserted in slot, right? No problems there.

Yep! Only one slot for it to go into, since it's a mini-ITX board.

Did you connect the power cables to the gfx card? This is #1 mistake most often made causing no output to display.

Yep. It has power going to it, though I'm going to pull the PSU again and make sure it's coming from right rails. The card has 2 x PCIE connectors that I have going directly into 2 separate 12V rails (25A each). The Antec TP-750 Blue has 4 separate 12V rails at 25A each, but I wanted those to go directly into the PSU instead of the ones that come out of the PSU, to make sure I had enough power. The card's fan spins up so I know it is getting power, but now I'm wondering if it isn't enough power. I'll report back.

BL.

 

[Going Bald]

Yep! Only one slot for it to go into, since it's a mini-ITX board.



Yep. It has power going to it, though I'm going to pull the PSU again and make sure it's coming from right rails. The card has 2 x PCIE connectors that I have going directly into 2 separate 12V rails (25A each). The Antec TP-750 Blue has 4 separate 12V rails at 25A each, but I wanted those to go directly into the PSU instead of the ones that come out of the PSU, to make sure I had enough power. The card's fan spins up so I know it is getting power, but now I'm wondering if it isn't enough power. I'll report back.

BL.

You need to be using the 2 8 Pin cables hard wired into the PSU, not any of the modular plug-ins.

 

[bradl]

You need to be using the 2 8 Pin cables hard wired into the PSU, not any of the modular plug-ins.

Why the 2 8-pin cables, when the Radeon HD6950 that I have only requires 2 6 pin cables?

BL.

 

[bradl]

An update.

Pulled the power supply, and indeed, it was going to the right plugs on the 12V rail. Same ones I had been using before in the previous build. Either way, I pulled those and went with the ones that are hard wired into the PSU. Turned on the machine and...

nothing.

I know I haven't blown the PSU, because it worked with the onboard GPU, and I know that the video card works fine. So that had me thinking that the only other unknown is the BIOS on the video card, as it was flashed and unlocked on the previous machine. Since the card has dual BIOS, and I only flashed one side of it, I flipped to the other BIOS, which was still stock/factory, powered on the machine, and I'm in business! HDMI comes up.

I haven't had a chance to connect both monitors to this, as that will be done tonight. But I'm at least up and running now.

BL.

 

[bradl]

figured it out.

Normally one would assume that if you plug in the HDMI cable into the first row of ports, that it should disable the DVI port, though the miniDisplayPorts should still work. So I plugged the DVI cable of the second monitor into the second DVI-I port on the card, which disabled the monitor altogether.

That was the mistake, as plugging the HDMI cable in does not disable the DVI-I port on the first row of ports. Plugging my DVI-I cable into the DVI port on the first row got both monitors working for me.

Also, since I unlocked it to a 6970, I played it safe and flashed the primary BIOS back to stock got me up and running. Sometime in the future I'll flash it back to a 6970. But for now, I'm all good!

BL.