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Does dead short on a Pcie conector indicated capacitor short or something else more likely?

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I bought a parts only HD7950 as I needed the fan/cooling assembly. There is clearly a dead short: 1.2 ohms between + and - on the 6 pin connector just above the large line of capacitors. The other connector has no problem. The first two can capacitors directly under the connector show a short but there are no obvious signs of problems. No leaks, popped top, discolored board, nothing to indicate a problem. Not sure if they have the short, maybe the short is somewhere else. I can plug it in and power it up if I use only 1 pcie cable. It does not work but at least it is not smoking.

It is a real pain to replace caps. Best I have done is use a dyke to cut them out and leave long leads to allow easy solder. I have an x-4000 station but the air never gets hot enough to unsolder old work.

I was wondering how likely it is the caps that went bad.

Thanks for looking.
 
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I don't believe you have dead ceramic caps, it's quite a rare trouble.
A much possible scenario is a dead TOP FET in one of the VRM phases, that has been shot through, and it has a low DC path to the ground right now.

Check all the TOP FETs, and maybe you'll find out the dead one.
 
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Who said anything about ceramic caps? The "can caps" he's talking about are no doubt aluminum polymer. Not that they're very likely to ever die either. Most manufacturers spring for the good ones that are rated for 10K to 20K hours @ 105°C. But it's possible(or likely, if it's been run with higher than its rated voltage and/or at a higher temperature) that one could kick the bucket earlier than it should. And, AFAIK, they almost always fail in closed circuit mode(less something I know, more something I've learned from experience).

Anyway, they aren't that expensive(nor difficult to replace with a decent soldering iron). I'd start by replacing all of them. Then move on from there if that doesn't fix it. I've gotten into a bad habit of replacing all the radial can caps on all the used hardware I buy. Whether they need it or not. Why? Basically brand new after that.
 
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pre heat the area then add leaded solder + flux, then try to remove the old solder. flux is your deoxidizing friend and the leaded solder lowers the melting point.

personaly id remove the suspect cap(s) and test again.
 
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Location
San Antonio, Texas
System Name 15 systems running boinc all built from parts individually bought and new and used except Area51
Processor i9-7900x, 2@Q9650, x5470, 3@Q9550, i7-950, 2@x5680, 6@E5620, x5675, x5570
Motherboard 3@dell, 4@msi, eVga, 3@asus, gigabyte, 3@hp. One of dell is Area51 only one I ever bought complete.
Cooling all of the hex core are liquid cooled as well as the Q9650s and that i9 & i7
Memory 8 to 12 gb except Area51 has 32.
Video Card(s) 570, 650ti, 670, 770, 1050ti, 1060, 1070, & rx570, 7850, 7950 & yes, I contributed to 1070 shortage
Storage 64+ TB in USB3 storage, all for my blu-ray & dvd collection.
Display(s) Pair of 23 inch cheap.
Case One is LianLI one of my kids gave me, about 1/2 are open air boinc farm. Can I pimp them?
Audio Device(s) Yes, got a Yamaha amp and 7.1 speakers
Power Supply tried to get all 80+ bronze or gold, but some are losers
Mouse Yes. I hate glides but sometime got to use them. Optical track-ball nice but out of my price range
Keyboard Surface pro 4 has a keyboard that keeps falling off.
Software 3@ubuntu, 11 @ windows 10. My kids run several macs and a win7 system.
Benchmark Scores About 80-90 grc a day but will drop out of the grcpool and start solo mining shortly
Removed 2 metal "cup" caps, had no effect. Not worth any more effort and the fan / cooler is needed for an AMD S9000 anyway.

I have found it expedient to just clip out the bad caps and use a Dremel to drill out the old leads. Nothing to unsolder.
 
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Display(s) cibox something or other 23" 1080p " 23 inch downstairs. 52 inch plasma downstairs 15" tft kitchen
Case 900D
Audio Device(s) on board
Power Supply xion gaming seriese 1000W (non modular) 80+ bronze
Software windows 10 pro x64
its not to bad desoldering things. i use hot air to pre heat, then flux + solder, then i use solder wick and the iron with a chisel tip for through holes, for surface mount i just use the hot air + flux, i like to use tacky flux.
some people like solder pumps but i genuinly dont get allong well with those..

as for your card.. you can always clip or solder on a low voltage low amp supply to it and see what gets hot. best to use a variable power supply though.. but as you said its not worth your time, so thats always a factor. but i tend to want to know what the issue is with stuff and fix them if its possible. Its always nice to do it.

it was probably a mosfet that was shorted though unless its something obvious but you just havent seen it.
 
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I have two method of removing capacitors. The super dirty quick way, I just use pliers & twist the capacitor, then you are left with just the capacitors leads in the hole. Then use a soldering iron with the pliers to remove old capacitor leads. Anyone here doubt what I am saying, "TRY IT NOW" on any dead component you don't care about & post your result in this thread. I only use this method on though hole capacitors. Do not use this method on SMT components, even thou it does work on some SMT capacitor. SMT COMPONENTS NOT RECOMMENDED.

The other de-soldering method is standard, one capacitor lead at a time.
 
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Joined
Feb 3, 2018
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Location
San Antonio, Texas
System Name 15 systems running boinc all built from parts individually bought and new and used except Area51
Processor i9-7900x, 2@Q9650, x5470, 3@Q9550, i7-950, 2@x5680, 6@E5620, x5675, x5570
Motherboard 3@dell, 4@msi, eVga, 3@asus, gigabyte, 3@hp. One of dell is Area51 only one I ever bought complete.
Cooling all of the hex core are liquid cooled as well as the Q9650s and that i9 & i7
Memory 8 to 12 gb except Area51 has 32.
Video Card(s) 570, 650ti, 670, 770, 1050ti, 1060, 1070, & rx570, 7850, 7950 & yes, I contributed to 1070 shortage
Storage 64+ TB in USB3 storage, all for my blu-ray & dvd collection.
Display(s) Pair of 23 inch cheap.
Case One is LianLI one of my kids gave me, about 1/2 are open air boinc farm. Can I pimp them?
Audio Device(s) Yes, got a Yamaha amp and 7.1 speakers
Power Supply tried to get all 80+ bronze or gold, but some are losers
Mouse Yes. I hate glides but sometime got to use them. Optical track-ball nice but out of my price range
Keyboard Surface pro 4 has a keyboard that keeps falling off.
Software 3@ubuntu, 11 @ windows 10. My kids run several macs and a win7 system.
Benchmark Scores About 80-90 grc a day but will drop out of the grcpool and start solo mining shortly
Connected a 12v battery to leads and within seconds spotted the problem
But I don't have any replacement parts and there might be more problems than just that device maybe??
maj_smoke.png
 
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