MSI frozr III hd 7950 - powers up but no video output and not detected.

bigcatface11

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Oct 30, 2011
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I recently just purchased a MSI Frozr III 7950 (3GB) as a re-furb model from overclockers.co.uk. Currently the card will power on (fans spinning) but will not display video and it cannot be detected by the device manager. This card has already been RMA'd and it came back with no errors so it is clearly something else.

My current set-up is:

Motherboard - Asus M4A89GTD PRO/USB3
CPU: AMD phenom II 955
RAM - 8gb (4x 2gb) Patriot G-skill (1333MHz)
Graphics card - sapphire HD 4850 (this is what the 7950 will replace)
PSU - Gigabyte ODIN GT 550w. (w/ 2x 6 pin connectors)
HD - 1x SSD and 1x HD

The original set-up is working 100% ok and has never experienced any problems.

Things I have already attempted:

1/ Updating system BIOS to most current version.
2/ trying 7950 in both PCI-E slots.
3/ uninstalling all current ATI catalyst drivers and installing all drivers required for the 7950 (Catalyst 14.4)
4/ using the 4850, I tested both PCI-E 6 pin connectors as one may not have been providing power, both are ok.
5/ changing Graphics priority in the BIOS from IGP to GFX0.
6/ changing graphics priority in the BIOS from IGP to PCI.
7/ Trying both video outputs on the 7950 (HDMI and DVI).
8/ Resetting the motherboard's CMOS.
9/ Switching the 7950's BIOS to its secondary BIOS.
10/ RMAing the card (As i said before, it came back with no errors).

I originally suspected it might be an issue with the PSU, as it is a bit old, but it is showing non of the classic symptoms of underpowering such as random crashes or BSOD's even when under stress.
CPUID hardware monitor shows all voltages as within limits even while playing games at max settings on the 4850.

I'm literally at my wits end. I have attempted all the solutions I have read online and nothing has worked thus far. Is there anything I am missing??

Thanks,

Bigcatface

 
Solution
its 100% stone cold lock your power supply.

that is a very rare, 4 rail power supply. which means it will only deliver 123W and 18A on one of the 12V rails... it will NEVER power a 7950. Get a new power supply.

furthermore, reading a review of the power supply indicates the 2 6 pin plugs run on separate rails... and one of those rails doesn't even give the advertised 18A & 123W that gigabyte claims it gives. running a gpu on 2 rails is inadvisable in the best of situations but running one on an unbalanced load is worse.

no, throw that junk out.


that said there is no promise the 7950 will work even with a new power supply (i'm just guaranteeing it WONT work with your current power supply), i would test it on someone else's computer to verify MSI bothered to test it.
 

bigcatface11

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Hi Ingtar, thanks for your answer.
Can you please post the review that found the rails didn't supply the advertised ampage? I've found an old one by jonnyguru that could be it but that only showed incosistencies between P-tuner values and the actual readings for amperes.
Also, can you please explain how seperate rails is an issue? this isn't a challange I'd just like to understand what you're talking about so we're on the same page.

I will test the card on another rig but I doubt that's the issue. Overclockers tested it themselves and said it was kosher. It would be seriously bad press if they were in the business of ripping off customers.

thanks,

Bigcatface
 
well, i'll try to break it down.

that is a 200W gpu that requires 24A on the 12V power rail

NONE of the 4 rails on that power supply can deliver that type of power on any 1 of the 12V rails. Splitting rails and attempting to power the gpu with 2 rails tends to cause load balance issues. most gpus can't boot with load balance issues, furthermore it's doubtful the 2 6pin plugs that come on that psu can deliver a full 24A and 200W to one gpu even if load balance wasn't a problem, because one of the rails one of the 6pin plugs is on shares it's power with the cpu, which means it's can't deliver the full power.

 

bigcatface11

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Well no chance of that; the 8-pin CPU plug is definitely in use.
Where are you finding this information? All I have to go from is the manual and various reviews. JonnyGuru seems to be the best so far. He defines the rails as:

+12V1 4-pin ATX12V and first two wires of 8-pin EPS12V
+12V2 Second two wires of 8-pin EPS12V, red PCI-e connector
+12V3 Main 20+4-pin, all Peripherals
+12V4 Blue PCI-e connector

Assuming this is correct, it appears i can get full load from rail 4 but rail 2 is shared with half the EPS12V. Seems to me like a very odd way to do it, but I've never built a PSU before...

Ok, imagining I can't Jerry rig something with this which power supply would you recommend buying? I think around 750w would be the highest I'd want to go.
 


your info is matching mine.

i mean you can try to run it split rail... many gpus will run it like that with the right power supply that does a great job managing the load balance. even then there are gpus that just won't run split rail.

i would suggest if you're going to replace the power supply to get a well made unit from this list. (nothing lower then teir2)

https://community.newegg.com/eggxpert/computer_hardware/f/135081/t/45344.aspx?Redirected=true



 

ninogui

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I would not blame the gigabyte odin 550w

because I have it running my setup for years (meaning about 9) and it´s one component that never broke down or had any problem whatsoever
And the setup is

- mb maximus formula
- 1x sapphire 7950
- 1x ssd for boot
- 2x hd in raid 0
- 1x additional hd
- 1x creative platinium elite pro pci card
- 1x 2 port usb 3 pci card

last but not least the q6600 bearlake is running oc´ed to 3.4 ghz and the gc most of times runs oc´ed too

thing is start to eliminate variables from the problem, try another videocard or the internal radeon 4290, if you are overclocking set it all to default and go from there
if all this works then yes you might have a broken mb lane, capacitor or circuit
 

bigcatface11

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Good news! I've managed to get it all to work!
The problem was that the card required the extra input (Sense1) found in an 8-pin PCI-E plug in order to work. By simply using a £5 6-pin to 8-pin adapter I managed to fix the problem. Normally this isn't required but I guess for this MSI card it is.

Ingtar, thank you for your suggestion but I think you were too quick to blame the PSU. Had I listened to you I would have thrown £60+ down for a new part that was completely unnecessary.
Also, I ran Unigene Valley in order to stress the GPU while checking P-tuner to monitor the PSU. The system is completely stable and not a single rail reached above 10A making the 18A limit completely sufficient. What you wrote about the rails not being able to deliver enough current for this card was flat out wrong.
I just hope that the next person who has this problem sees this cheap, easy fix instead of being lazy and just throwing large amounts of money at the problem.

-Bigcatface
 


I didn't realize you were using a 6pin plug in an 8pin input. that will cause a power issue.

and at it's heart this was a power issue. You're right though, i did jump to a wrong conclusion, due to not having all of the fact. something was tickling the back of my head when you said you were using 2x6 pcie plugs, but i didn't really focus on the fact tahiti gpus come with a 1 - 8pin and 1 - 6pin power plug.

silly oversight on my part, considering i OWN a tahiti gpu.
 
Solution