The repasting suggestion appeared fairly early.  It was almost described as something one should do even if there were no serious faults showing.  This led to many miners being taken offline in a period when return was still pretty good but hashrate rising so a gainsay motive isn't out of the question.  How many S3 owners, attempting the repasting, were not electronic techs with SMT experience who would not comprehend that flexing a circuit board tends to damage SMT solder joints.  It could very well be that falling hashrate happened almost always after repasting.  I'd venture we don't know.

Repasting per se didn't damage, flexing may have.  The hashing boards and the inside heatsink do not part easily as you know.  That difficult separation would result in many just 'trying harder' with the result hashboards were bent/flexed.

Throwing in my 2 bits, I experienced the deteriorating hashrate phenomenon after installing a newer firmware (I think 12/19).  After reverting back to 10/24 firmware, I haven't had that problem.

I feel like Linus in football season with Lucy moving the placed football causing Linus to fall.  I took your suggestion but didn't see any 10/24 S3 firmware so went to an earlier, 20140721, version and found myself back at the firmware I had before trying others.  I had worked my way up to 20141013 which repeatedly came up with GUI failures so I backed down to 20140811.  But you said earlier so I again tried the next earlier which was as I Mentioned 20140721, the LuCI.  Can't help feeling like I've been played, Lucy LuCI.

So the 20140721 firmware was replaced last night requiring me to replace the rebooting at low hashrate script and by this morning it had run twice for low hashrate, e.g. below 421.

Waiting on that liquid flux which only left California yesterday.

After restarting cgminer the second time since firmware change, there was an x on each chain on this S3#2.  x's at chain1#2 and chain2#8.  This, the S3 from Pines in Florida sold as new but arriving in an opened box, has had x's various times at chain1#2, chain2#6, chain2#8 and chain2#16 but as mentioned previously the chain2#16 was cleared by cleaning the ASICs with a brush and solvent as it sits near the intake fan and at that time I had the fan on full 12v continually and may have pulled in some debris that hit that ASIC.

ive repasted my s3s..

the heatsinks on these are on the outside.. you dont have to take anything apart.
its not difficult.. there is 4 screws and they are spring loaded.. meaning you cant over tighten them..

as long as you werent a complete idiot and put the heatsinks on upside down, you cant really screw it up.

clean the chips off, just put a dab of new paste on each chip, screw the heatsink back on.

when i took mine off there were 3 chips that didnt have any paste at all and 2 or 3 only had about 20% covered.

just make sure you use non conductive thermal paste..
i think i used MX-4.

My first S3+ should arrive any day, looking forward to it, woo!  I plan to factory reset it and flash with the latest firmware straight away, like I did with my S1.

As a hobby miner I love that I can pick up the older tech for a mere fraction of what it retailed new for.  Can't wait for the next gen to come out so that the used S5 price drops by 80%.

Hello, I come to you because I 've realized a problem of hashrate on my S3 no more than 200GH/s
here is the screenshot


http://img15.hostingpics.net/pics/827500antminer.png


Thank you in advance .

Just two PCIE connectors plugged closest to the RJ45 and it normally runs for six months minimum, I just look 2 days ago the low hashrate. 

Take a look at your screen shot, ASIC Status, one of your boards is dead, you're hashing with 1/2 an S3.