New info on 7900 series faults!!! - DEFECTIVE voltage regulators!

[EDIT: I'd like to AGAIN remind everyone that this COULD be a load of complete BS. Anti nVidia propoganda being smartly written by someone with lots of time on their hands and the urge to "stir shit up". Take ALL of this with a grain of salt. Mmmmkay? Need I re-iterate this point any further?]

This was just posted on the eVGA forums:

This IS a cross-post from the general forum. Mods, if you dont delete it, feel free to leave it here or move it to the General Forum (where I posted it first):

To all,

There are a batch of 7900 cards with bad voltage regulators on them. These cards were shipped from China. Nvidia IS aware of the bad batch of voltage regulators and is waiting for the batch to run out before updating the regulators with a batch of higher quality regulators. They are ignoring higher than normal failure rate (50-60%) in hopes of filling demand, and that is why prices are dropping on 7900 series video cards.

These voltage regulators are located on your card directly below the GPU on the underside of your card. The regulators are a 3-pronged small chip with the terminals bent at a 90-degree angle.

These regulators will and can degrade over time (esp. 3-6 months). The OC or Superclocked versions of these 7900 cards will exibit artifacting and graphical errors before the standard clocked version due to the higher current draw of overclocked cards.

This problem effects ALL Nvidia 7900 series cards, regardless of make (IE: BFG, XFX, EVGA...) and is the direct fault of Nvidia, NOT any card distributor.

This problem was originally addressed from HardOCP.com under the mis-understanding that it was a problem caused by overclocking from vendors, which it is not. BFG, XFX and EVGA ALL are trying to improve quality control to solve this problem, but EVGA has shown the best effort so far.

Please do NOT return ANY defective 7900 series card to any retailer (store) that the card was purchased from. You may get another defective card. Instead, please use any RMA procedure from the vendor that distributed your card as they will test your replacement card and try to assure your RMA will be trouble-free.

I have forwarded this issue to HardOCP, TomsHardware, Anandtech and Overclockers.com for further investigation.

Your welcome.


Al Capone[CC]

Now apparently this information comes from an internal source in the eVGA software engineering department. If this is true it sure does provide a good explanation for the problems that seem to affect most of the current run of 7900 series boards.

This isn't a far fetched explanation by any means, especially when you consider that ALL 7900 boards are actually made at a singular facility (Flextronics) and then distributed to the board partners (eVGA, BFG, XFX, etc) for cooler installation and branding/SKU.

I'd be willing to bet the VRM in question is the one just to the right of the GPU area when looking at the backside of the card. On my defective 7900GT thats on it's way back to eVGA, the voltage regulator chip in question is an AZ7805D linear regulator made by Advanced Analogue Circuits. The datasheet is here (PDF).

Here are photos of the VRM on my defective 7900GT:



It looks like the sane or similar VRM is on the GTX boards in the same spot on the backside of the card.

<EDIT>

Below is a photo of the same voltage regulator chip on my replacement card sent by eVGA on Thursday evening by next day air:





As you can see it's the same chip from the same manufacturer, but the week and batch number is obviously newer. There are also some pretty obvious signs of re-soldering so I'm thinking that eVGA might have replaced this chip before sending the card out to me.

AGAIN - I don't know for sure that this is the voltage regulator in question, but it's the only one on the underside of the card. (There is an similar one on topside of the card near the DVI outputs). This could be the regulator in question, it might not be, or the whole story might be a very legitimate looking false rumour.

What kind of ticks me off about this, if it ends up being true, is that passage about [H]ardOCP addressing the issue under a misunderstanding. If there was any misunderstanding going on it sure as heck was on nVidia's part as they are the one who placed the blame squarely on the board partners for shipping pre-overclocked cards. Hmph!

I'm glad the issues are finally being revealed as they truly are instead of all this white noise we've been seeing recently on the topic. I've been pointing out all along that these issues don't just affect the pre-overclocked cards. They affect the stock clocked cards just as badly, it just doesn't manifest as fast as it does on an overclocked card.

I'd be willing to bet this same VRM is used on the GTX somewhere, as there seems to be almost as many GTX users with failing cards the past couple of weeks. [EDIT: Yup, same damn voltage regulator in the same exact spot on the GTX cards]

Wow...

Thankfully I bought a 6800GS

This is going to be a pain in the ass for retailers/suppliers.

thanx for info, ill bet mine fails soon too.

::Hugs his X1900XTX....and burns face on 90C metal::

Originally Posted by 0V3RC10CK3D

::Hugs his X1900XTX....and burns face on 90C metal::

::Hugs 6800GS...and warms face on 41C metal::

I am glad that I didnt upgrade my system. I was planning on buying the eVGA 7900GTX Superclocked . And a new Cpu and Mobo as well.

Doesn't make sense to me. You telling me that nvidia is not only supplying the GPU, but also the supporting electrickery?

Doesn't make sense to me at all. A voltage regulator isn't a new or especcially hi-tech or proprietary piece of equipment. It's a fucking voltage regulator. Theyv'e been around for decades. Why in hell would nVidia supply the V regulators to card manufacturers? There are many manufacturers of high-quality electronics components...

Is nVidia forcing card makers to go with a certain brand or component? If so, WHY?

Doesn't make sense to me at all, and I call BS. While the vregs may be the cause of the artifacting, it looks to me more like the component SPECIFICATION is limiting the overclock, simply because the voltage regulators (as specified in the reference design) simply cannot provide more juice. I don't think it's a case of bad binning or anything like that. The vregs simply need to be more beefy in order to support non-reference clock speeds.

EDIT: Ah, nevermind, I need to learn to fucking read! Okay, so the boards were all made at the same facility, so it's certainly possible.

Originally Posted by PhyberOptic

Is nVidia forcing card makers to go with a certain brand or component? If so, WHY?

No.

As I understand it all of the 7900 boards (and most of the first runs of the other nVidia boards) are manufactured by a company named FlexTronics. The boards are almost completely assembled there except for the coolers which are added by the board partners (what you called "Board Makers") once they recieve them. The board partners do the branding (and BIOS alterations if needed) and then box them up for retail.

nVidias reference design is what dictates the components used. As for wether or not it dictates this particular brand and model number of voltage regulator, who knows. The component may have just been the cheapest and easiest for flextronics to get hold of.

This doesn't mean the board partners can't make their own cards, and a few of them actually do months after a particular GPU is released. I think BFG has a couple of 7900 models that are actually made in-house.

Heh, yeah I read the quoted "bulletin" but not the text that followed. Certainly is possible

This actually makes me wonder about a lot of the computing industry, and the wool that is pulled over our eyes in terms of what we think we are buying, and what brand we think we support.

If this is true I think this might be frontpaged somehow....

nice point but, then again the reference cards are also failing.

Originally Posted by Templar_X

nice point but, then again the reference cards are also failing.

I think you missed the point....

How many reference cards do you reckon stay at reference clock speeds?

And what about those hidden "nvidia/Ati speedup" settings that you find in many bioses...

"The vregs simply need to be more beefy in order to support non-reference clock speeds."

this would only make sense if only the overclocked were breaking.. i think

So buying a gerneric card isn't bad really?

Well my 7900GT aint that old and it has AS7805 VRM not a AZ one. Also batch nummber is starting with letter A.
Mine is a XFX Vivo version with stock speeds(black PCB).

Well We all look at VRM module nummber but crusial nummbers are 7805 and those nummbers state it's positve line 5 V regulator. Like 7905 would be negative line and lets say 7812 would be 12 V regulator.

It's 1 A part hence not realy a monster. I wasn't tracing lines to find out whats purpose of it but place on a PCB and it's current and voltage rating tell's me it ain't that important VRM as once found on PCB on other side next to a power connector.
Still if it mailfunctions it will make odd things.

Any 78xx can be rated for different current and voltage rating. How is it going to preform deppends on it's specs, cooling solution as wel as quality of input side. In thi case it's SMD part and cooling is provided by PCB it self and it should be in specs. Though on grafic cards there are so many components using PCB for a cooling. Even a GPU transfers lot's of it's thermal energy thrue it's BGA. OC it and situation gett's even worse.

If VRM is overloaded it will try to supply how much it can. If a input is stable and can supply demanded current everything deppends on VRM. There are safety margins hence VRM can deliver bit more then it's rated for. Though if it's non stop overloaded and badly cooled it will die. There is a reason why Ultra cards have had double VRM circuits and GT cards have had single one. Although it was posible to OC easy GT to Ultra speeds VRM cicruit was suffering. thats also a reson why Ultras where better OC-ers although they have had same core. Mostly PCB is a same just higher models have more components.

On other hand if input side can't deliver stable voltage VRM will work even worse making fluctuations.

Overloading VRM will cause voltage drop, instability and eventual failure.

Bad batch of VRM will crash and burn.

It doesn't suprise me all Nvida cards are build at one place.
Many products are made in single Factory and then delivered as semi product to a branded factory.
Like cores and CCD's and TFT and even a optical drives and mediums come just from few factories. Dell is not making their own TFT panel for 2405, they just use egsisting panel.

I see also why nvidia would need to have controll over a components choise specialy about VRMs and elcos on PCB. Those are crusial for cards stability. Also if part supports a 1 A current and current on stock speed is like 800mA there is a small margine for OC. Though if they use 5A part on same place there will be enough current to burn something behind it. Also if 5A part is like 30 cents more exprencive on 1 million of cards using same part it's a lot's of money for unneeded capacity.

If 1A rated 7805 works and they have used bad batch it's just bad luck. Hence Factory that made VRM's is to blame. Nvidia is one to blame covering it up.

Well I gues all new cards are made with good VRM's and cards that fail will be RMA-ed so We doo not need to suffer to much.

Damn shame cause 7900GT are great cards for godd price.

BTW although AC Silencer and Zalman VF coolers cool core with almost same efficiency and dispite a fact that AC cooler has exhaust system I've went last few times for Zalman as it cools pcb as well as GPU and ocupies less place. My 7900GT is cooled with VF900 and I'm very satisfyed. It fits my SN25P as well.



MD

Would be nice if Kyle and Brent commented on the issue or contacted Nvidia for a more detailed explanation. If this is true, Nvidia should have done a full recall, kind of like Ford did with thier explorer series a few years back, instead of knowingly sell thier customers faulty equipment. AEG and now this. I am quickly loosing faith in Nvidia.

Originally Posted by MD

Well my 7900GT aint that old and it has AS7805 VRM not a AZ one. Also batch nummber is starting with letter A.

>snip<

MD

good post! i'm wondering if sticking a ramsink on the VRM will help cure problems.