I need help to repair my Ati Hd7950 card (FINALLY IT IS REPAIRED)

[dingdan]

¡Esta publicación está eliminada!

[Fassou]

Celebrating April Fools' Day? or are you serious.

Salu2!

[Filrond]

Well, it's serious. No, I'm not celebrating April Fool's Day "foreigner".

This is what happens when you've been doing this for a long time, but you trust too much in some people and then one day they play a trick on you.

I was able to confirm that they are SMD capacitors. I've seen PCBs from other PCI Express cards from ATI as well, and they all have those same 16 SMD capacitors, although the size varies from one to another. The ones from the 4870 are the most similar in size.

And I now know they are capacitors because many of those PCBs have serigraphy that identifies the components and it says: CXXX on all those SMDs, that is, the C always indicates a Capacitor. If they were resistors, they would come with R.

They must be standard for all PCI Express cards to have those SMD capacitors there, the problem is knowing if the value is standard or if it varies from one to another.

There are two options:

The most insecure, putting the two from the Hd4870.. They are not exactly the same size, it varies a little bit. A difference of thousandths, but it varies.

The safest but that complicates things, remove one of the SMD capacitors that are next to each other and measure it outside with a capacitance meter to find out its value and then solder it back and buy a few for the ones that are needed and to have in reserve.

The BIOS is not it, because that was the first thing I changed. To see if it was that, I put the generic one from Amd, the Tahiti Pro Bios from June, which improved the performance of the graphics card. It was a BIOS that reviewed the performance of the Hd7950s, because at first it was not the expected one. This BIOS worked with all the Hd7950 cards with the reference PCB, like mine.

The store people wash their hands, they didn't sell me this card... such and such. I have a ticket but in my ticket it says Power Color Hd7950... honestly I hadn't noticed, I took the computer directly to the store to have it assembled there and therefore I didn't see the box, nothing, just the ticket and the card, along with the typical accessories of cables and that.

They say they sold me a PowerColor and therefore now it's my word against theirs. I have data and confirmation from Amd that this card is from Dell, (Dell also confirms it to me in the Dell forum), but I repeat they claim that this is not the card they sold to me. Moreover the value was 297 Euros, it doesn't reach 301 Euros. As you know, any fraud crime that is less than 301 Euros is considered a minor offense. Translated, that to recover the money or take them to court I have it in Chinese, although I have reported them.

What I have clear and I've realized, is that I have to repair this card myself if I don't want to throw away almost 300 Euros.

I have knowledge of electronic repair, in fact I also have a soldering station with a heat gun. A few years ago I was on hardware and console forums, especially on Playstation 2, making repair manuals and console modchips.

But I can complicate my life less and take it to impextrom, for them to measure one of those SMD capacitors and buy and solder the ones that are missing. Years don't pass in vain and my eyesight is not as good as it used to be.

If I fix this problem, I'll put here how I solved it. Because it's a very rare problem, but I've already seen that it has happened to more people than it seems abroad. And I think those SMD capacitors are standard, (the value may not be), in that area for all PCI Express cards.

Thanks for the help and greetings

[Bm4n]

I would measure the adjacent of the same position on the pair next to it and put some of identical value, go to an electronics store if you don't have a way to measure them.

[Fassou]

Reading your first post again, you say that this card is ready to work in PCI Express 8x slots, but it fails in 16x ones.

If the problem is that, then you can cover the extra contacts and leave it as 8x using a 16x slot.

I leave you some posts in which you will be able to see images of how it is done.

Salu2!

Sources: Tom's Hardware - PCI Express Scaling Analysis and Tape off lanes

[Bm4n]

It would be the simplest thing, but it would be a shame that you didn't fix it anymore not only because the card can use the 16x width (which may be noticed little or nothing) but because it's a good graphic, the "repair" will cost you little and it's very simple. And well maybe even so it doesn't work for you, you see very strange things with the "custom" hard for these brands...

PD. Some BIOS didn't allow you to configure the width of the PCI-E?, or are they imaginations of mine.

[_Neptunno_]

Wow, after reading the first post you realize how many scammers there are in this country. Of course it's a good thing you're lucky to have knowledge of electronics, because maybe you can solve the problem... which is 300€!! And that's if you can outsmart those who ripped you off...
Good luck and let us know.
Best regards!!
P.D: I imagine you haven't tried contacting Dell support, right? they might give you some clues or help.
I worked for a company that did (among other tasks) support for Dell's support, and they worked great (I'm talking about 2007)

[Filrond]

I can't do anything against the store. They gave me a ticket that didn't specify that they had sold me a PowerColor Hd7950 and that's what they're claiming now, that they didn't sell me this Dell card.

If I were a newbie in this little world I would have an excuse, but I'm not, so I made a mistake and trusted these people too much.

I've already reported them, but with that ticket saying PowerColor Hd7950 I have it in Chinese and besides it doesn't reach 301 Euros for the scam, so it stays as a minor offense.

The problem is that the card doesn't work on most motherboards and there are quite a few that I've tested it on. It only works on the old Msi 775 and a Msi Dual Xeon Quadcore 771 5000X from a friend, (it has a total of two quadcores with eight processors).

That is, it only works on two Msi motherboards. On several others from different brands and different chipsets, including that of my new updated computer, an 1155 with an Asrock P67 Extreme 4 B3 and an I7-2600 it doesn't work. And I've tested it on a similar one from Asrock with the Z68 chipset and PCI Express 3.0 support and it also doesn't work, (from my brother), on others from gigabyte, Asus, etc.. quite a few and I repeat it only works on the Msi. On a Gigabyte X38 Dq6 775, it did work for a while in the second PCI Express slot, I rebooted, installed drivers, surfed the Internet, but when I was going to test the 3DMark, before even starting it, suddenly the screen went black and it never worked again on this motherboard.

I put it back in the Msi and it worked on both the first time and without problems, tests, games, etc…

**
In the overclockers forum, the user Bobnova confirmed to me that they are capacitors and that they are 0.1µF (100NF) and 0402 format, he also told me that with a voltage greater than 5v they are already valid.**

**" Originally Posted by Bobnova View Post
Those are 0.1µF, 0402 package capacitors. If you replace them, should work fine.
It looks like the pads are still there, so you just need to get some caps and solder them on. The tricky part of course is that they're tiny. Any voltage rating over 5v or so is fine.

I'm surprised it works at 8x, as those pairs are for 3x and 4x respectively. "**

I've searched the Internet and found messages with those values and about PCI Express from people with similar problems on their card and some of these capacitors were missing.

In addition, I found a Philips PDF Datasheet from April 30, 2005, about PCI Express that said the following:

"PCI Express requires AC coupling between transmitter and receiver. The AC coupling capacitors for both differential pair signals must be the same value, same package size, and have symmetric placement. If possible, TX traces should route on the top layer.

The capacitor value must be in the range of 75 nF to 200 nF (100 nF is best). The 0402 package size is preferred, and 0603 is acceptable. C-pack is not allowed.

The breakout into and out of capacitors should be symmetrical for both signal lines in a differential pair. The trace separation for routing to pads must be minimized in order to optimize tight coupling between the signal pairs."

I bought capacitors of this type and value from an American seller on Ebay, specifically for about 8-9 euros including shipping, I got a pack of 100 units of 0.1µF (100nF) 0402 SMD capacitors with a 10V voltage rating in the XR7 format (supports temperatures from 45º to 125º.

And when I was already happy waiting for them to arrive to solder them, it turns out that this message was sent to me in the HardForum forum:

Now I'm really confused, the user airthimble sent me the link to this PDF, it's written by PCI-Sig (PCI Express) and is from 2008:

http://www.pcisig.com/developers/main/training_materials/get_document?doc_id=0a73787e8b6cc2b746ba2c2140a4ed768e93e9df

and it says:

"

As the next generation of PCI Express is defined, the information throughput will double and yet the symbolrate will only move from 5 GT/s to 8 GT/s. There are some significant changes and challenges:
While 5 GT/s communications used 8b/10b encoding to limit the longest occurrences of consecutive 1’s and 0’s, 8 GT/s will use scrambling.

This has system budget and signal integrity impact on both transmitter and receivers. Baseline wander due to the long runs of consecutive 1’s and 0’swill impact the available eye height.

AC coupling capacitors of 220 nF will be required in order to reduce the baseline wander.

The combination of higher datarate and channel length up to 20”combine to cause Inter Symbol Interference (ISI), in addition tojitter from reference clocks and transmitters. These will limit the eye opening width available".

Now I'm really confused….. 100 NF or 220 NF... I guess I'll have to desolder one of the ones right next to the missing ones and measure it, just to be safe.

The idea of trying to update the card's bios was the first thing I tried, with its design it's the Reference from Amd, I was able to flash it with the Official Amd Tahiti Pro bios from June 2012, the famous bios of the Hd7950 that raises the clock and memory speed to compete with its Nvidia rivals and improve the performance of the Hd7950. But in my problem it didn't serve for anything.

The problem as it's clear in the photos and as they confirm to me, is a hardware problem and as long as those missing capacitors are not replaced it will never work on 16X motherboards.

I think I'll take it to the people at impextrom, because unlike me they have professional electronic machinery that can measure these capacitors without having to desolder them from the motherboard and by the way they can measure them and if the ones that come are the correct ones, then they can solder them with that machinery, if not then they can get the correct ones and solder them.

Because if I have to do it myself, even with a soldering station and heat gun, you're risking frying the PCB when desoldering one of the soldered ones (without frying it), measuring its value, then soldering it back and buying the ones that are missing... well better that people with professional machinery do it, they take it out easily and without frying anything.

Regards and thanks for the attention

[Fassou]

From what you say, it seems that in slots x16 of PCI Express 1.0 plates it works for you, including that X38 you mention. Did you try again in its first slot?

Have you tried covering the contacts with tape?

Regards!

[Filrond]

Thanks to user Bobnova from overclockers forum.

Thanks to user airthimble from hardforum forum.

Thanks to all users from all forums for their answers and messages.

UPDATE:

THE VGA CARD HD7950 IS COMPLETELY REPAIRED. IT WORKS PERFECT AT 16X AND IN ALL COMPUTERS, IN WHICH BEFORE IT DID NOT WORK.

THE SMD CAPACITORS ARE 220NF AND 0402 FORMAT

I FINALLY BOUGHT THESE SMD CAPACITORS:

0402 X7R 6.3V

CERAMIC CAPACITOR 0.22UF 6.3V, X7R, 10%, 0402
Capacitance: 0.22µF
Capacitance Tolerance: ± 10%
Dielectric Characteristic: X7R
Voltage Rating: 6.3V
Capacitor Case Style: 0402 ^1005 Metric]
Operating Temperature Range: -55°C to +125°C
Capacitor Terminals: SMD
No. of Pins: 2

Then, I took the card and the capacitors to my local store in Vigo for electronic sales and repair IMPEXTROM, so that they could solder the missing capacitors with the professional machinery that we, the most modest electronic users, do not have. I have a soldering station with a heat gun and I have done quite a few repairs and chip assembly on consoles, but I preferred to leave this work to professional electronics like those at IMPEXTROM, who have, I repeat, professional machinery with which the most modest users can only dream.

It has come out perfect. It is already completely tested and the card works perfectly. It was those two SMD capacitors that made it not work at 16X and also only worked at 8x on MSI motherboards.

I leave a record that, starting from 2008 and the introduction of PCI Express that went from 5 GbTransferencia per Second to 8 Gbytes of transfer per Second, (2.0, 2.1 and now with 3.0), the capacitors used in that area to communicate the PCI Express connector of the card with the PCI Express connector of the motherboard, are of value 220Nf and format 0402, must be at least 5v or higher.

I obtained this information about formats and values thanks to the users of two other English/American forums, Bobnova and airthimble.

**Then, following the clues they gave me, I searched the internet for Intel datasheets on PCI Express and found the information.

5Gb of transfer per second in the first PCI Express up to 2008, these had capacitors of 110Nf and format 0402.

8Gb of transfer per second or higher (PCI Express 3.0). From 2008 onwards, these have capacitors of 220Nf and format 0402.**

The information remains.

Regards

[Fassou]

Thanks to you for the SPAM, and for not responding to my suggestion :alone:

Salu2!

[G0D1N0]

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[Filrond]

Sorry about the Spam, I just wanted to indicate where I took it in the end to have the two Smd soldered... I have good knowledge of repair and soldering, but sometimes it's better to leave it to professionals with professional machinery... and if I mentioned the name, it's because nowadays many electronics and electronic repair shops have closed and in many cities, like mine Vigo, they are starting to be a rare sight.

The Spam from the other forums. Sorry, it was to thank only the two users from those forums who gave me the most important and vital information that led me to be able to repair the card.

My apologies and if you want to edit it to avoid Spam, do it, I don't want to offend this forum.

Sorry finally, but when you answered me I already knew that this was not the solution and that it could bring me many problems if I did it wrong... In the end I already knew from the information of those users and from the Intel Datasheet on Pci Express and Pci Express 2.0, 2.1 and 3.0 that the solution to my problem was to solder again those two Smd capacitors that were missing and that their value was 220 Nf and format 0402.

I didn't answer any of you until I fixed it, because even though I'm not a teenager anymore.. (SIC), jajaja, I'm studying and I've been taking exams these weeks.

Regards