One man’s garbage = an [H]’s 7800GTX SLI

I would bid right now, But I really don't want to take a risk, especially when I don't have a job right now.
 
nice info,it does give the thought that it can be done again if one has guts and money to spend
 
Guys do ourselves a favor and leave this with family/friends and the [H] community. Don't want too many people finding out about this!

It'll drive prices up to the $50-$100 range which defeats this purpose.
 
Servant of Shodan said:
This is an expansion of a “Post your favorite card of all time” post I made.

I have no idea why this works! Logic tells me that is should NOT work. But nothing ventured, nothing gained! The moral of the story is, fellow [H]’ers, never give up!
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I call BS, a broken card is a broken card how the hell can it fix it self magically
 
SX2233 said:
I call BS, a broken card is a broken card how the hell can it fix it self magically
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The faulty part is probably shorting the circuit, removing the part removes the short and allows the POSTing process to continue.
 
i just got a pair of 7800 gtx's on ebay that were listed as non-working, untested for about $80 with shipping. I'm going to see if it's the same thing. I'll let you guys know.

edit:

video card one has the same burned out mosfet in the same location... will take pics of it and post the results... i haven't had a chance to look at video card 2 yet...
 
Methadras said:
i just got a pair of 7800 gtx's on ebay that were listed as non-working, untested for about $80 with shipping. I'm going to see if it's the same thing. I'll let you guys know.

edit:

video card one has the same burned out mosfet in the same location... will take pics of it and post the results... i haven't had a chance to look at video card 2 yet...
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2 days later, any news?
 
mnewxcv said:
2 days later, any news?
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Sorry. Nothing yet. I got caught up on some family issues that I need to resolve before I get the card in and working. I have pics, just not the time to get you guys a full report. I promise I will.

edit: Well, I was able to get the mosfet off on both of the cards as carefully as I could. However, the damage was really extensive. The solder mask underneath the mosfet was a little scorched, but it peeled away to reveal the real damage. The trace was fried, the ground plane wasn't attached to anything and just curled up and whatever was left of the fiber of the board under that area was just burned up. You can't see it on the other side of the card, but the scorching goes all the way through to the other layers. And this is on both cards too. Oh well, it was a gamble, but I would do it again.
 
K, I got two 7800GTXs from the same online recycler guy on ebay. $41 a piece and they dont work :mad:
 
flip3d said:
K, I got two 7800GTXs from the same online recycler guy on ebay. $41 a piece and they dont work :mad:
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What was their condition? Did you check all the mosfets? How about the core under the heatsink? Also take a look at the back of the board. I have seen boards with other parts broken off or missing that I was able to fix by finding a simple replacement.

If you take some pics and post them, maybe we can trouble-shoot.
 
I only have the camera on my phone so the pics arent so great.

PIC-0026.jpg

PIC-0027.jpg

PIC-0028.jpg
 
Servant of Shodan said:
What was their condition? Did you check all the mosfets? How about the core under the heatsink? Also take a look at the back of the board. I have seen boards with other parts broken off or missing that I was able to fix by finding a simple replacement.

If you take some pics and post them, maybe we can trouble-shoot.
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The burnt mosfet on mine is marked Q8. What did you use to pull yours off?
 
flip3d said:
The burnt mosfet on mine is marked Q8. What did you use to pull yours off?
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Yeah... those pics aren't the greatest. The burnt mosfet was in a different place on all three of my cards. On yours, it looks kind of like the one in dead-center is off-colored - some burned-looking coloration around the chip. Is that correct?
 
Servant of Shodan said:
Yeah... those pics aren't the greatest. The burnt mosfet was in a different place on all three of my cards. On yours, it looks kind of like the one in dead-center is off-colored - some burned-looking coloration around the chip. Is that correct?
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Yep yep. Q8 is the one in the center.
 
Extract with extreme prejudice!!

Seriously, daintily remove it with needle-nose pliers in a twisting move to crack through and remove the black ceramic (?) material. That will likely expose the shiny core, which I removed with a very fine, razor-sharp x-acto hobby knife.

Take time and work delicately.

You don’t have to completely remove it all down to the PCB (although on one of mine I did, and it was still OK – the other two still have some shiny material, but enough of the damaged matter is removed so that a) the circuit is cut in that location or b) the circuit still connects somehow… :( I still don’t know why this works in the first place. :(

Good luck. And may the Force be with you.
 
I bought one off of ebay and mine burnt out number 7. Let me tell you all I would rather walk through fire than to try removing that mofset again. It is very small and not easy at all. I will let you know if my video card bursts in to flames when I test it out.
 
This is Epic! Maybe there is some hope in that pathetic excuse for a body... insect...

I have an X1900XT at home; one of the MOFSET's is cracked and thus the card will not post. I'm thinking it's worth a try removing the damaged MOFSET when I get home from work. More then!
 
Hi,

What is the power spec for a single unit? I have a 430W PSU. I am thinking this card is going to need a min of 400 Watts?

However, nice find and best of luck to you if they stay strong and work hard for your graphic needs.

Shaggy
 
Mine worked too. This is pretty cool. I popped it in and played Battlefield 2 for a while. No artifacts and the temps stayed under 65C. The mofset heatsink didnt even get hot to the touch after use.
 
There are six more on ebay right now. I am thinking the prices are not going to be really cheap anymore.
 
Hmm, my brother's 6800GT blew out a while ago and it took had some burnt stuff around one of the thin-topped chips by the MOSFETs (not sure what they are) so I took some needle nose pliers and it literally cracked with a small bit of pressure into dust and ash. I cleared off the area but I don't have a system to test it in (I really don't feel like putting it in my own because I *finally* got it working 100%)

What are those things anyway, what I broke off? There were four MOSFETs and each one has a smaller glossy-topped thin square looking things that are covered by the MOSFET heatsink.
 
To the OP and anyone else who has attempted this, weren't you afraid of a potential fire when turning the system on? Or is a fire not possible by just removing a MOSFET? Me is a n00b at electronics. :p
 
I wish I was smart like you guys...
I would buy 3 or 4 of these in hopes of getting one to work.

However I am not and will be buying a 8600GTS(or slightly better) in a retail box.
 
I'm just using one right now because I dont have an SLi bridge yet. It really doesnt get that hot if you have good airflow. I covered everything on mine with AS5 so it stays well under 70C.
 
Ya the one I paid $70 for on ebay untested was garbage...still doesn't work even to this day...I had a huge post about it here. I'm so pissed about it, because the other 7 people who got them all got working cards. I spoke to a couple of the other winners on the phone about it even. I have such terrible luck. They were pulls from Gateway machines btw.
 
jaguax said:
To the OP and anyone else who has attempted this, weren't you afraid of a potential fire when turning the system on? Or is a fire not possible by just removing a MOSFET? Me is a n00b at electronics. :p
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I was. I left the side cover off the case and watched it like a hawk while I was testing it. I am pretty sure that smoke and fire are always possible when attempting something like this.
 
Would not this risk the MB too. Toasting the PCie Slot would not be good thing.

DM
 
First off all, my humble congrats to the OP. Amazing story.

Then I did deeper and find many folks like myself. Into computers and the challenge they present. I actually have a BFG 7800GTX on my shelf. It's been there since I upgraded to a 8800GTX and Vista about 3 weeks ago. I had trouble figuring out the klaxon that occasionally occured, and the locked up my PC. I've since come to realize power save mode in Vista and my 8800GTX don't mix. But since shifting to max performance I've played games like HL2: Epi. 2 all the way through without incident. Sorry... got off track. ;)

ANYWAY, I love that you guys are trying this. I'd buy one for under $40 to give it a go, but yes... prices seem higher since a fix for these cards is found. And pulling a 8800GTX just to try 7800GTX in SLi doesn't make any bloody sense at this point. :)

That said, finding a good 7800GTX to pair with my old card should I ever buy a SLi board to throw them in WOULD be interesting... VERY interesting! :D

Best wishes to all, and to those yet to play... good luck!!! ;)
 
I would highly recommend NOT overclocking any of the cards that were "repaired" by removing the shorted MOSFET. Until someone does some power calculations for what is dissipated in each MOSFET at load with one MOSFET removed and referring to the datasheet for maximum input power, current, voltage as well as dissipation, I'd be very careful.

I wonder if these MOSFETs can be bought online and soldered back on as long as the traces and pads are not destroyed. If someone had a schematic of the voltage regulator sector of this card then it might be possible to reconstruct your own circuit and bypass the original traces (i.e. ghetto wiring job). I doubt microwave frequencies are present within the MOSFET network so electrical length doesn't matter much.

Good luck with the ones that work though - it sure is a deal! Hopefully they continue to work after a year :).
 
DarkenReaper57 said:
I would highly recommend NOT overclocking any of the cards that were "repaired" by removing the shorted MOSFET. Until someone does some power calculations for what is dissipated in each MOSFET at load with one MOSFET removed and referring to the datasheet for maximum input power, current, voltage as well as dissipation, I'd be very careful.

I wonder if these MOSFETs can be bought online and soldered back on as long as the traces and pads are not destroyed. If someone had a schematic of the voltage regulator sector of this card then it might be possible to reconstruct your own circuit and bypass the original traces (i.e. ghetto wiring job). I doubt microwave frequencies are present within the MOSFET network so electrical length doesn't matter much.

Good luck with the ones that work though - it sure is a deal! Hopefully they continue to work after a year :).
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I dont know about anyone else here, but I dont think any human can re solder these connections. I think there were at least 8 and they were tiny.
 
I just did a search on 32N03S, which I believe is what the top of that ship reads (looking at the OPs pictures) and came up with this part number: BSC032N03S. It is a surface mount component with eight pins and these are not that difficult to solder one just needs to get some solder paste. Now searching Digikey.com for that part I came up with this: BSC032N03SG. Please note Digikey charges a $5 handling fee for purchases under $25. These chips are the BSC032N03SG and are slightly different than the BSC032N03S. To read up on the datasheets of both, just google "BSC032N03S datasheet."

Edit:Direct link to the datasheet
 
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