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Other => CPU/GPU Bitcoin mining hardware => Topic started by: glub0x on August 24, 2013, 09:26:39 AM



Title: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: glub0x on August 24, 2013, 09:26:39 AM
Hello, i'm stumbling on a VERY strange problem.
Back to home after 3 weeks away i realised one of my rig is in poor condition : 2 cards have the rear fan dead (hard to rotate by hand do not rotate on power).

Take off the the cards put a gigabyte in and let the rig mine for the night. Today i realise the 2 other sapphire cards are in poor condition too, the rear fan is VERY slow compared to another rig i have with the same cards... They also make more noise and one of them sometimes stop...

The fan have not been blocked by anything i can see. The cards are 4 7950 sapphire vapor-x no overclock running between 70 and 85 this summer.... I bought them together 3 month ago and had 0 problem before.



rig is
4 7950 vapor x
MB MSI GD-55
ALIM XFX 1050Watt


I have another rig like this one running for 4 month with the same configuration except MB which is MSI GD-85 and one of the card is the sapphire flex oc. No problem so far but i'm anxious...

I suspect the alimentation but it looks in good condition ... On a previous wattmeter test the rig was eating arround 980 watt.

Otherwise i'm lost ...


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: HellDiverUK on August 24, 2013, 08:46:24 PM
Seized up fans have nothing to do with the motherboard or power, or whatever.  They're just shitty fans, and the ones seizing up are probably running hotter according to their location in your rig.  Those crappy little sintered bearings aren't designed to run flat out 24/7.  The microscopic amount of oil in them dries up quickly.

You could try stripping the fans down and putting a drop of light machine oil in the bearing of the fan motor (I use hair clipper oil, or paper shredder oil depending on what's handy).  Twirl them round a bit to get the oil in to the bearing and they should work OK again.


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: fasmax on August 25, 2013, 02:35:19 AM
I think they are using cheap fans.
But seems strange if all came from the same rig.
Are your 7950's still under warrantee?
 
The fans on my 2 Gigabyte 6950's lasted about 2 years at 100%.
My warrantee expired so I have to replace the fans at $15 each.


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: glub0x on August 25, 2013, 04:25:27 AM
it s all under waranty.
What is strange is that i have 7 7950 the 3 other ones are on another rig and look good.


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: crazyates on August 25, 2013, 06:14:00 AM
Just reoil them. Takes like 5 minutes per GPU, and they work great after. I've reoiled dozens of fans the past year, and they all work wonderful after.


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: AMD FTW on August 25, 2013, 02:12:57 PM
All 7950 fans suck regardless of manufacturer's brand if they use those twin or triple fans on the heatsinks. The cards that use a centrifugal/squirrel cage fan are great. Between my rigs and brothers we're running around 40 7950's and all of them have fan issues along with the previous generation 6950's that had the same type of fan. Now my 6870's that have ran continuous for 2.5 years have been PERFECT and also my HIS 7950's Ice Q's have been perfect since new. Now we only purchase this 7950 because of this fan design.

Forgot to mention also ambient room temp is 75 F and each rig (7950's) has a nice box fan behind them blowing directly across them along with all cards having cable risers allowing maximum space between cards so they aren't baking each other. I triple crossfired msi twin frozr 6950's in the motherboard and found that even if the cards were run at around 80 C the heat was to much for the center card and the fan would literally seize after a month of mining. This was repeated twice on purpose and I personally believe these fans can't handle excessive heat and run at 80% + continuously.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814161420


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: glub0x on August 25, 2013, 08:53:43 PM
Just reoil them. Takes like 5 minutes per GPU, and they work great after. I've reoiled dozens of fans the past year, and they all work wonderful after.
how do you do that ? it seems dumb, but i can't open the fan to see the bearings.
same problem as that http://www.tomshardware.com/answers/id-1702224/oil-fans-sapphire-radeon-7950-vapor.html
Also i don't want to ruin the waranty...
very boring problem...


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: crazyates on August 26, 2013, 10:05:57 AM
Just reoil them. Takes like 5 minutes per GPU, and they work great after. I've reoiled dozens of fans the past year, and they all work wonderful after.
how do you do that ? it seems dumb, but i can't open the fan to see the bearings.
same problem as that http://www.tomshardware.com/answers/id-1702224/oil-fans-sapphire-radeon-7950-vapor.html
Also i don't want to ruin the waranty...
very boring problem...
Take 2 minutes and read this thread: https://bitcointalk.org/index.php?topic=52192.0
You might have to drill a small hole in the top shield of the motor itself, and then inject oil in thru there. Remember to seal the hole after, tho.


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: glub0x on August 26, 2013, 07:02:20 PM
Just reoil them. Takes like 5 minutes per GPU, and they work great after. I've reoiled dozens of fans the past year, and they all work wonderful after.
how do you do that ? it seems dumb, but i can't open the fan to see the bearings.
same problem as that http://www.tomshardware.com/answers/id-1702224/oil-fans-sapphire-radeon-7950-vapor.html
Also i don't want to ruin the waranty...
very boring problem...
Take 2 minutes and read this thread: https://bitcointalk.org/index.php?topic=52192.0
You might have to drill a small hole in the top shield of the motor itself, and then inject oil in thru there. Remember to seal the hole after, tho.
thanks i think i won't risk the waranty.
I'll go RMA and try to get a HIS ICEQ as said above to give it a try...


Title: Re: Dead rear Fan on 4 7950 vapor-x on the same rig.
Post by: crazyates on August 27, 2013, 12:44:30 AM
How well do those IceQ cards work? I heard they can be a little unstable when trying to get high hashrates, as compared to the Gigabyte 7950s or the Sapphire 4L cards, which are almost always butter smooth when trying to get high hashrates. I like the thought put behind the cooler, but I wouldn't want you to get an inferior product.