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One mans garbage = an [H]s 7800GTX SLI
- Thread starter Servant of Shodan
- Start date
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.
I'm sure you can OC the card, you just need some decent cooling for the remaining mosfets. There are waterblocks available to replace the little black heatsink but its just not worth doing because they're so damn expensive.
he did remove the mosfet, look at it carefully...
And its funny how many people here said to themselves "wow It is so easy I go do that now... i go buy 2 cards at once... at way more then the OP did, and I sure I fix them good"
Really really funny...
Anyways, its a nice thing but I wouldn't bother with it since 7800 is not DX10, and thus of no use to me...
I also have a theory as to why simply removing it worked... Cards are designed so that they put as many parts as they want on them and it works... that way they can save money on lower end cards by simply not having more ram / mosfets / other parts soldered to card... So when you completely remove it the circuits just work around it in parrallell as they were designed to do in the first place.
If you notice a lower end card will ALWAYS have a socket for more ram and other controllers that its higher end sibling has, only the sockets are empty with nothing soldered in.
Seeing as a mosfet is a voltage regulator it just means your voltage is slightly less regulated, which means you need to have cleaner power comming in... but seeing how atrociously bad many PSU and Mobos are (like the ones in the gateway machines that burned those cards?) it isn't really an issue for anyone with a decent rig.
And its funny how many people here said to themselves "wow It is so easy I go do that now... i go buy 2 cards at once... at way more then the OP did, and I sure I fix them good"
Really really funny...
Anyways, its a nice thing but I wouldn't bother with it since 7800 is not DX10, and thus of no use to me...
I also have a theory as to why simply removing it worked... Cards are designed so that they put as many parts as they want on them and it works... that way they can save money on lower end cards by simply not having more ram / mosfets / other parts soldered to card... So when you completely remove it the circuits just work around it in parrallell as they were designed to do in the first place.
If you notice a lower end card will ALWAYS have a socket for more ram and other controllers that its higher end sibling has, only the sockets are empty with nothing soldered in.
Seeing as a mosfet is a voltage regulator it just means your voltage is slightly less regulated, which means you need to have cleaner power comming in... but seeing how atrociously bad many PSU and Mobos are (like the ones in the gateway machines that burned those cards?) it isn't really an issue for anyone with a decent rig.
Servant of Shodan
[H]ard|Gawd
- Joined
- Dec 28, 2002
- Messages
- 1,777
Solder paste, eh? I confess I have never heard of the stuff.
I just might buy a fourth card to see if that little replacement mosfet and the solder paste works. I don't want to do it with the SLI'd cards I have up and running, though. If I messed up something after getting this far, I would not forgive myself any time soon.
Thank you, Piccol0z! For both the paste and the digikey link.
DarkenReaper57
2[H]4U
- Joined
- Oct 2, 2003
- Messages
- 2,173
With adequate cooling, yes. I didn't take into account that someone would go through so much trouble as to fit the area with a better heatsink or waterblock. Nevertheless, excellent cooling will only get you so far, and will not protect you from currents, etc that well exceed the limits of the each chip.
All I am saying is it would be prudent to find out the maximums of these chips and be sure not to exceed them. Yeah, they might overclock fine for 6 months, but the added stresses (whether it be extra current, voltage, power, higher temperatures, etc) surely wear on the components. They might be fine, might last a few hours, or might last a few months. It is all unknown until some calculations are done.
I'm just looking out for the guys here so they don't end up with fried cards
.Agree, with that kind of burnt video card installed, I won't dare to leave that system on 24/7 and what happen if a fire were started without knowing when during asleep. It would be safer to full shutdown when not using the computer. Besure to install a smoke detector nearby.
All the cards are going for 60+ dollars now on ebay. This is a gamble that has been worth the effort to the people that have tried it here. All the people that bought this gateway in the first place should ask for their money back. This is obviously a QC problem with this card.
Thanks Shodan servant for sharing Ebayers sure started to love you!
It's fun and risky no doubt!
A fun story I made up after reading the thread :
A n00b [H] member buys one from ebay (7800gtx) for $70, tries his best! No luck! Cries! Decides to ebay it back without telling that he tried
Now "Servant of Shodan" want to have fun and suddenly! A $24.99price tag got his attention "OOooo a bargain! He says!
So, our friend SoS manages to fix it with extra work and says " Boy the owner is so unlucky with his attempt to repair it" As it works for him!
Now our first friend a n00b [H] member tracks things to find that it was his! Hmmm need to say more? *commits suicide*
***
We learned the word "n00b" and the number "Zero".
Darn am bored! Yeah at my office! Where else!
Ebayers sure started to love you!It's fun and risky no doubt!
A fun story I made up after reading the thread :
A n00b [H] member buys one from ebay (7800gtx) for $70, tries his best! No luck! Cries! Decides to ebay it back without telling that he tried
Now "Servant of Shodan" want to have fun and suddenly! A $24.99price tag got his attention "OOooo a bargain! He says!
So, our friend SoS manages to fix it with extra work and says " Boy the owner is so unlucky with his attempt to repair it" As it works for him!
Now our first friend a n00b [H] member tracks things to find that it was his! Hmmm need to say more?
*commits suicide****
We learned the word "n00b" and the number "Zero".
Darn am bored! Yeah at my office! Where else!
Hawkeye170
n00b
- Joined
- Oct 18, 2007
- Messages
- 20
??????
SPARTAN VI
[H]F Junkie
- Joined
- Jun 12, 2004
- Messages
- 8,763
Wow, these busted cards are just a few $$ shy of "working" cards on ebay.
8lack8rain
Limp Gawd
- Joined
- Nov 11, 2005
- Messages
- 372
I'm still interested to see if the mosfets can be replaced (soldered). Not needed but just curious. Anyone going to try?
Hi,
Well I won one of these gems from the same guy. Here is my story.
I got the card a few hours ago. It was a pleasant surprise on the door step. I said it's better than bills! So I got the card on to the work bench. Brought my PC to the bench. First thing was check the mosfets. All nine of mine are in great condition. I reinstalled the heatsink after a dash of AS 5. The card gets installed and nothing. I said crap what is it now. Then the system spins up and I get video. While in POST, I see a small orange flame while watching the card. The flame gets blown out and the pc is powered down instantly.
Now I am back downstairs on the bench with the card out. I find the culprit. It was the small diodes? right next to the heatsink. Number C329 had burnt to a crisp. I gently removed the remains. Cleaned up the area and reinstalled. The card boots up with this electronic component missing. So I ran it through set up. Everything works. I ran 3D Mark 05 (It was all I had for a quick test) The card ran fine. Not too hot on any of the heat sinks. Then I gamed with it for about 1/2 hour. Same thing. Seems to work fine.
I guess these were a good buy. I think the card I got was probably "good" to begin with. However when good power was applied, it cooked that one thing which might have been bad from the factory for all we know. It is an upgrade from a 7600GT OCed by EVGA which was pretty good. The only thing I have notice and I do not know where the actual root of the problem might be. The card does not overclock. The memory will seem to be pushed but the GPU will not go past factory stock. I think it might start with Nvidia's control center. It might require a 3rd party tuner. However, I am not going to push the system right now since I am only running a 430 Watt PSU.
Hopefully good luck ahead,
shaggy
Well I won one of these gems from the same guy. Here is my story.
I got the card a few hours ago. It was a pleasant surprise on the door step. I said it's better than bills! So I got the card on to the work bench. Brought my PC to the bench. First thing was check the mosfets. All nine of mine are in great condition. I reinstalled the heatsink after a dash of AS 5. The card gets installed and nothing. I said crap what is it now. Then the system spins up and I get video. While in POST, I see a small orange flame while watching the card. The flame gets blown out and the pc is powered down instantly.
Now I am back downstairs on the bench with the card out. I find the culprit. It was the small diodes? right next to the heatsink. Number C329 had burnt to a crisp. I gently removed the remains. Cleaned up the area and reinstalled. The card boots up with this electronic component missing. So I ran it through set up. Everything works. I ran 3D Mark 05 (It was all I had for a quick test) The card ran fine. Not too hot on any of the heat sinks. Then I gamed with it for about 1/2 hour. Same thing. Seems to work fine.
I guess these were a good buy. I think the card I got was probably "good" to begin with. However when good power was applied, it cooked that one thing which might have been bad from the factory for all we know. It is an upgrade from a 7600GT OCed by EVGA which was pretty good. The only thing I have notice and I do not know where the actual root of the problem might be. The card does not overclock. The memory will seem to be pushed but the GPU will not go past factory stock. I think it might start with Nvidia's control center. It might require a 3rd party tuner. However, I am not going to push the system right now since I am only running a 430 Watt PSU.
Hopefully good luck ahead,
shaggy