Quote from: FuryFever on April 02, 2015, 12:58:28 PM

I was actually overclocking my Antminer S2 with some success on the STOCK power supply (1,000 Watts Enermax). I took the clock frequency values posted on the first page and played around with them and found I had the best luck with 216M (215.625 MHz per chip). With this setting, I had increased my average hash rate on the miner from around 1,008 GH/s or so stock to around 1,092 GH/s overclocked. My hardware error rate only increased to 0.96% or so (under 1%, so not bad...) and I was even getting mining pool side hash rates reported from this machine in the 1.09-1.12 TH/s range!

But, I wanted to see if I could get more out of it than that. I had read on this thread that if you wanted to overclock the Antminer S2 more, you would need to get a bigger power supply so you could supply all the ASIC chips with more power to run them at a higher MHz clock speed. So, ... I purchased a LEPA G1600, which is a 1,600 Watt continuous (1,700 Watt peak power) fully modular power supply to swap into my Antminer S2. I completed the swap Tuesday night (March 31) and have been playing around with the chip frequencies and voltages since then and I just CANNOT get it to run any better than it already was on the stock power supply at 215.625 MHz chip frequency!! What gives here?

Any help towards maxing out my Antminer S2 would be greatly appreciated! Thanks in advance and I look forward to any advice you guys can give me!

Well, it looks like possibly overclocking my AntMiner S2 plus the sudden heat wave that we got this week killed it. I have no idea what happened to it, but all of a sudden I noticed on Friday that it just stopped hashing. Now, it had been mining overclocked at 215.625 MHz and averaging 1,092 GH/s without needing a reboot for over 35 days straight. It had been running rock solid with temps only in the 48-56 degree Celsius range. However, this week the outside temperatures really skyrocketed all of a sudden (along with the humidity). We had 75-80 degree Fahrenheit days all week, and then this past Friday [May 8], it hit almost 90 degrees out with like 78% humidity! I hadn't had a chance to dig out the air conditioning units and install them yet, so my house was pretty unbearably hot. It was around 92-93 degrees Fahrenheit upstairs and in the basement where my miners are it was around 94-95 degrees, despite the natural cooling that a basement can provide in the summer.

Because of the heat and humidity on Friday, I had a bunch of my miners go down, including my AntMiner S2. (I also had problems with one of my CoinTerra miners and one of my AntMiner S5's also overheated and shut down. I had one board in my S5 go over 80 degrees Celsius, so it shut down.) However, my AntMiner S2 acted very weird. The web interface went down so I couldn't remote into it anymore, but the miner was still on (or at least the power supply was still running). The red light on the front of the miner was on and the display on the front of the miner was blank. So, I unplugged the miner and left it off for about 10 minutes to cool down (as I assumed it overheated, even though I never saw the temperatures go over about 60 degrees on it).

However, when I plugged it back in, it is only mining at about HALF capacity for some reason! The temperatures are also MUCH lower than they were - only around 42-48 degrees Celsius. The weird thing though is that I have all 10 boards up and all 64 ASICs per board are showing as good (Displaying "o" in the ASIC Status and not "x"). So, there seems to be nothing that would be preventing the miner from running at 1 TH/s, yet I am only getting 511.6 GH/s out of it! I have no clue what is holding it back, unless I fried some of the chips in it. However, if that was the case, then shouldn't it be showing a bunch of dead chips in the ASIC Statuses?

Does anyone have any ideas on what could have happened, what to look for, and/or how to get this miner back working at full capacity again? Should I just pull out and reseat the boards and try to clean it up a bit? How can I tell what is preventing this miner from hashing at 1 TH/s? Also, when I had to restart the miner, it reset back to 200 MHz per chip from being overclocked at 215.625 MHz, but it should still be running a lot faster than 511.6 GH/s. It has been running for almost 2 days now since it shut down on Friday and the hashrate has still not increased on it at all and the temperatures are still only in the mid 40 degrees range. Any help getting this miner back running again at full hashing capacity would be greatly appreciated. Thanks!