Failed 6800nu volt mod - Any hope?

[Cybercat]

I tried to perform a core volt mod, but unfortunately I was an idiot and soldered in the wrong places (and did a sloppy job of it too, which I spent hours scraping excess away with a knife). I don't know what I messed up on it now. When I first put it in, there was just silence. The screen didn't come up, and after a few seconds, the motherboard started beeping at me. It didn't pop, no smoke, nothing. I've taken off the volt mod, and all remnants I could of my soldering on the card, and still the same thing, so something, despite there being no detectable sign of it, must have fried. The card feels completely cold when it's plugged in, nomatter how long I leave it sitting there on. Power isn't being routed through the card, and it may be from the regulator chip that controls the voltages. My sloppy soldering and heavy scraping left it damaged. I'm just wondering if it's possible to replace the regulator chip, or the capacitors, mosfets, or whatever to get it working again. They have elaborate mods to put a second molex connector on GTs, and it looks hard. But I'm willing to go through with it more cautiously, and get it done right, whatever it takes. I don't have a lot more to loose anyway, it was a good card, but it's a paper weight now.

Thanks to anyone who takes the time to read this.

[persivore]

Can you check if there is any Vgpu voltage being regulated (you can check this by looking at the voltage at a Vgpu read point).

[nebuchanezzar]

That's some tough luck. I would think, but can't be sure that unless you killed something in the gpu there's always a chance to resurrect it...but troubleshooting a pcb like that can be hard. Good luck and best wishes to you.

[Cybercat]

Hmmm, interesting. I wasn't expecting the core voltage to read anything, but it was actually showing 0.525v. Somehow I severely undervolted it.

[Suffocation]

I had the same thing on my msi k8n, i had 0.3 on my vdd.
You can try to replace the chip (oid) where you did the voltmod on.
Didn't do it myself, i rma'ed my mobo

[persivore]

Can you post some pictures of the mod area. It might be possible to repair it if the only problem is the undervolted core voltage :)

[Cybercat]

I'll takes pics as soon as I can get a hold of a digital camera. May not be 'til tonight or tomorrow.

[Cybercat]

http://img.photobucket.com/albums/v74/Cybercat/Misc/modproblems.jpg

Sorry for the crudity of the picture, I don't have a highend camera to deal with.

You're looking at the backside of the card (without the GPU or RAM chips) at the rear of it. The voltage regulator chip you see there is where I soldered one end of the resistor, to the first leg on the bottom row there. Some solder got on the other pins and I had to scrape at it a lot to keep the connections separate. The 3D voltage leg that I was supposed to solder to has actually bent up off the PCB before, so I had to try and solder it back down. But all the scraping I did made the solder hard to make stick to it.

The second circled item is where I wasn't supposed to solder. I scraped a lot of that away too, and poked the hole through, getting as much solder around the rim off as possible.

Obviously I'm not very adept with a soldering iron, and cleanup as a result makes the whole thing messed up. :( I still don't even know if that leg on the voltage regulator is making a decent connection or not, but I really can't do any better to reconnect it.

[CaTalyst.X]

You might be able to do the hard vgpu mod and save the card, but i doubt it *RMA* or throw away. If u cant get it working, can i have it for parts? ill give u the cost of ship. LMK

-CaT

[Cybercat]

Yes but if it's running at 0.525v now, what pot would I need to bring it to at least 1v?

[Cybercat]

Well, I tried soldering a 10k VR (this time I know I did it right) and nothing's changed. *sigh* Thanks anyway guys. Looks like I'll have to work toward getting another card.

[persivore]

You could try building a new regulator to supply the card.

[Cybercat]

You could try building a new regulator to supply the card.
:eek: How do I do that??

[persivore]

:eek: How do I do that??

What are your electronics skills like ;)
What voltage does the GPU use, and does it change depending on the load it is under (I assume it does).
I'll try to draw up a circuit diagam for a simple switching regulator in the next few days if you want. You could also try reducing the 3.3v line down to the correct voltage for the GPU using diodes.

[Cybercat]

What are your electronics skills like ;)
What voltage does the GPU use, and does it change depending on the load it is under (I assume it does).
I'll try to draw up a circuit diagam for a simple switching regulator in the next few days if you want. You could also try reducing the 3.3v line down to the correct voltage for the GPU using diodes.
My electronics skills are very limited, or else I probably wouldn't have killed my card in the first place. But if you'd really draw up a diagram I'd forever be in your debt! lol, plus I really don't have anything to lose.

A typical 6800 standard has a 2D voltage of 1.1v and a 3D voltage of 1.2v. This can be changed by the card's BIOS, but I'm guessing I'd lose that feature, which is OK by me (just so long as it works). Memory voltage is also controlled by the voltage chip, and I believe the stock voltage is 2.6v. Obviously the card is fed power through the AGP slot and a four-pin molex connector.

Once again, I thank you for your support! :bows:

[persivore]

To check that the only problem with the card is the GPU voltage, you can connect 3 diodes in series with the 3.3v line to the Vgpu supply, which should give you around 1.2v. e.g. 3.3v 0---->|--->|--->|---0 Vgpu supply
You might have to remove/cut the existing VGPU voltage, but you should just be able to de-solder the inductor used for the Vgpu supply and connect the diodes to a Vgpu read point.

[Cybercat]

Heh, on second thought, I don't think I could do that. I wouldn't know where to begin to solder what diodes where or even where to get the 3.3v line from. Thanks anyway.

[kryptobs2000]

Cat had first dibs on it, but if he were to change his mind, I'd take it. If I fix it, I'd send it back to you as well (plus cost of supplies, and shipping). Cat is a very good vmodder though, so he'd be first choice imo, but just in case ;)

[Cybercat]

Cat had first dibs on it, but if he were to change his mind, I'd take it. If I fix it, I'd send it back to you as well (plus cost of supplies, and shipping). Cat is a very good vmodder though, so he'd be first choice imo, but just in case ;)
Well it didn't sound like Cat had any intention of sending it back if he managed to get it working, which, if it that was the case, I'd give you priority. I really don't have a problem sending it to either one of you guys, because right now the card is sitting in my "add-on card drawer" in my desk doing nothing.

If Cat could speak up about it once again and elaborate on the details of what he plans to do with it, that would help.

[kryptobs2000]

I think he planned to use it for parts, but he's a good guy, I'm sure if he fixed it he'd offer it back to you.

[CaTalyst.X]

Yeah man if i got it working i would definately send it back to you, but i dont think persivores idea w/ the diodes would work at all. I had this same problem w/ the vbt on an NF7 and i was able to get it working :) So if you would like send it to me and if i cant get it working ill even send it to krypto for ya if you would like :)

-CaT

[Cybercat]

Thanks! I'll send it to you then, Cat. Probably use USPS. Just PM me your address and I'll let you know how much shipping would cost. If you get it working, I'll pay you to ship it back.

[Cybercat]

*is still waiting for a response from Catalyst*

[Cybercat]

Oh well, I put it up on eBay in case anybody might remotely be interested in it.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5175910799

[CaTalyst.X]

Oh, sorry i havent checked this thread. Id really like to play with the card. YGPM

-CaT

[Cybercat]

Alright, auction is canceled. Let's hope you can work magic with the card. I've got my fingers crossed.

[CaTalyst.X]

Youre in luck, i managed to get a hold of a new voltage regulator, soldering it on this week and ill let you know if she fires back up :D

-CaT

[Cybercat]

:eek: w00t! Things are starting to look up. If anyone can do it, you can.

[kryptobs2000]

where'd you get the voltage regulator from?

[CaTalyst.X]

Dead Card, but thers nothing rong w/ the vreg on the card, person knocked off a diff vreg. This is the reason i ask for ppls dead hardware so i cna fix other peoples stuff.

-CaT

[Cybercat]

Cat, ygpm