Botched my first loop; dead 6950 with a new cap

MrWizard6600

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Hey gents,

I've been meaning to get into liquid cooling for a long time, so a couple years ago I bought one of the old asetek liquid cooling loops on clearance. I've been purchasing my way out of catastrophe ever since, and I'm starting to lose hope.

I'll let you read all about my first clusterfuck here.

My newest is that I bought a super nice EK 6970 block for my soft-modded 6950. I thought the reference boards were the same. They are not. There was a single cap that was interfering with my attempts to mount the block, so I took off said cap and soldered on a new one. I've never done that before with electronics this sensitive, but I had somebody who used to be a repair agent for Sony take off my cap, and it wasn't much trouble getting another one back on. The cap was 16V 140uF, but I couldn't find one at that rating, and my Sony guy said that it was just voltage regulation so a 16V 220uF cap would work just fine.

I'm also a little afraid that I've damaged surface components by mounting the water block on too tightly. From what I have, EK didn't supply me with any spacers, so I just ran the screws straight through the board and into the block. What I noticed was that I was actually deforming the board slightly by doing so (I didn't hulk this thing, and I didn't apply what I'd call an uncomfortable amount of force when screwing the board to the block, so I cant imagine I did too much damage). So having screwed these things on too tightly, I loosened them up a little bit.

Anyways, the card now gives me a black screen.

Furthermore, I had a 9800GTX+ that I was using as a stand in to get everything lined up. I spilled a single drop of my cooling fluid on it while it was running. It doesn't post either.

Any suggestions?
  • Was my Sony guy full of shit? Should I try to find a 140uF cap and replace the 220 one I put on?
  • Was the damage caused by me over torquing the screws? Should I bake my card? Anybody have a guide to do that?

I'll post pics if anybody thinks they'll help.

Thanks for reading,

-Geoff
 

pbassjunk

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Sep 17, 2012
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Preheat oven to 375F, bake for about 10-12 minutes. Remove everything that is removable and clean up any grease. You want the flat 'back' side of the card facing up so all components are facing down. Use a pizza tray or something and put some foil down, and ball up some foil to lift the card up off the tray - as minimal contact as possible.

I baked my 6950s after I was convinced I hosed them doing the Kuhler/ziptie method. Assuming I did actually do something, they're both running fine now. So I either fixed them after having broken them, or they weren't broken in the first place *and* I didn't break them when baking them.

Couldn't hurt!
 

jojo69

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You want the flat 'back' side of the card facing up so all components are facing down.

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I respectfully disagree with this one detail

also, many would argue that 10-12 min is too long, but time/temp preferences are a matter of much discussion
 

staticlag

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Was my Sony guy full of shit? Should I try to find a 140uF cap and replace the 220 one I put on?

The Sony guy was right. You can go higher on Micro-Farad rating, the only reason why most boards try and use the smallest rating cap possible is to save space, (because higher ratings are physically larger). No problems there at all.

As for you over-torquing the block on the card, The human hand can really give quite a bit of pressure, even though it doesn't seem like a lot to you, it may be enough to break sensitive components. It gets even trickier when you are tightening two things are are smooth, because what feels like resistance to you only comes from felt friction.

Example: say you put powdered sugar on a bolt and tried to tighten a screw on it. It will feel like you are really tightening it because the sugar is gumming up the bolt, but if you actually measured the stretch the screw is experiencing it will not be as much.

But... if you put oil on a bolt and tried to tighten a bolt on it you will not feel much resistance at all because of the lubrication. If you measured the actual bolt stretch it may be way too much and almost at the point of failure.

So human "feel" can be extremely deceiving.

A good rule of thumb I use for computer components is the thumb and finger method. Tighten all computer screws using only the fingertips of your thumb and index finger.

This isn't an airplane! (and if it was then you would have precision torque wrenches and can tighten to the precise amount every time)
 
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Crispy002

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Does the card still give a black screen even with the stock heatsink installed? If so, it might point towards needing a solder reflow or worse yet, might indicate some permanent damage has occurred.
 

MrWizard6600

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ok so in the debate of who gives better advice, HardForum or Bit-Tech, Hardforum wins (I figured I'd post there because so many of their mods are so incredible, but I guess the guys making those don't post on the boards or read "help me" threads)

Yeah, I should mention I've done a fair bit of work with electronics, and I was fairly certain that those caps were simply putting some space between that cards sensitive innards and what it suspects is a rowdy 12V line.

My work:


It sounds like baking my card is the best move? I'd like to ask this guy at lee's electronics whats going on.

So anyways, I discovered that the water block did in fact come with spacers they expected between the card and the block, so odds are quite high that I simply damaged the card by putting too much pressure on it.

The spacer:


So It seems pretty clear that I did infact over-torque the card. So what do you guys think is the problem, a solder joint on top thats cracked, or the copper withen the board? I'd imagine the baking strategy works to fix solder cracks, but if my problem is internal to the board, is it done?

Given that, is it time to start baking?

I'm inclined to think that if its a surface solder crack, then 5 minutes at 350 with the board facing up would be sufficient; the soldering job they do on these cards has so litter solder that I'd imagine it doesn't take long to start liquifying. Sound good?

A crack with one of the layers in the board I'd imagine is pretty rare. Its not that they use alot of copper, but I'd imagine that copper is pretty flexible. Actually I might just be hoping, since if the problem really is inside the board, I guess there's virtually nothing I can do about it.

Maybe if 5 minutes at 350F doesnt do it, I'll try 400F for 10 minutes.

Also, anybody looking to sell a Radeon 7970?

PS: the gunk on the side of the chip is not my paste, it was the OEM's. I decided against trying to clean it off entirely since it would be too much work, might damage the card, and wont likely cause any performance increase.
 
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Thermite Paste

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The Sony guy was right. You can go higher on Micro-Farad rating, the only reason why most boards try and use the smallest rating cap possible is to save space, (because higher ratings are physically larger). No problems there at all.
I thought it was the other way around, and it was the voltage that can be swapped? IIRC it's really just a minimum rating and as long as you use something higher you're fine. Not sure about the capacitance but I'd imagine that using something different would be bad since most circuits depend on a specific number...
 

onin

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Nov 25, 2005
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Just want to chip in, I recently parted out my old AMD rig. 2 days ago I replaced the original heatsink of 2 6950s to send to a friend, I used an EK universal block originally. Judging from your photos, that looks like different than one I had, Its either a non-reference card or a different version.
 

Arcygenical

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I thought it was the other way around, and it was the voltage that can be swapped? IIRC it's really just a minimum rating and as long as you use something higher you're fine. Not sure about the capacitance but I'd imagine that using something different would be bad since most circuits depend on a specific number...

Entirely 100% this.
 

MrWizard6600

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I thought it was the other way around, and it was the voltage that can be swapped? IIRC it's really just a minimum rating and as long as you use something higher you're fine. Not sure about the capacitance but I'd imagine that using something different would be bad since most circuits depend on a specific number...

The units are correct, if the cap is being used as voltage regulation, then you can have whatever capacitance you want as long as the actual voltage put over the cap is below the (advertised) break-down voltage.

Anyways, I baked my card for 8 minutes at 385F last night, no change.

So I guess I'm looking for a new graphics card :(
 
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