ANTMINER S2 Discussion and Support Thread

[freebit13]

Sounds like it might be the old problem of a corrupted SD card. Take it out and try to read it on your pc to see if it's still ok.

[RCMco]

Zelek,

I know this has nothing to do with your questions but in your post you stated that you have the units in a rack. Is it s server rack?  If so how is the temperature on the units?

I have 6 A2s and a few LTC machines and was thinking about buying a server cabinet from a place down the road but was concerned about the heat disbursement.

RCMco

[fullzero]

I'm I right in thinking that this is BBB controller failure? If so, it is possible to get a replacement?

I think your right.  I had one Bitmain BBB completely fail on me.  Good news is that you can replace it with an over the counter BBB; if that isn't the problem just return the BBB.

[mavericklm]

Any succes on underclocking and undervolting the s2?

I updated to last firmware(Wed Oct 29 10:13:19 CST 2014) and i see new options like Frequency 193M
Any ideea on what setting i need to put under Voltage?

THX!

[dogie]

My S2 (batch 2) stopped running 78 hours ago, after running flawlessly for months. It has been hashing since 2014-04-17, the only thing I did early on was replace the PSU with a Corsair AX1200i.

So after hashing for 9 months, all of a sudden it stops.

The display is blank and the red LED is on (red = bad sign, normally has a flashing green LED). The fans are working, and I can see the green Ethernet networking light flashing inside on the BBB controller. None of the lights on the hashing boards are showing.

The unit is in a stable environment inside a quiet rack cabinet. The other miners in the same cabinet are working fine (a KnCMiner October Jupiter which has been hashing for 1 year 3 months, an S1 hashing for 11 months, and a Spondoolies-Tech SP10 hashing for 8 months). Nothing physical (e.g. G-shock, liquid) has happened to the unit.

Looks like a failure of the controller, as the web page won't come up, and I can't even ping the IP address of the unit (which I have fixed on my router using DHCP Reservation).

I only have one S2, so I can't troubleshoot by replacing the controller board with one from a good unit.

I'm I right in thinking that this is BBB controller failure? If so, it is possible to get a replacement?

Assuming PSU is fine because those AX1200is are rock solid.

1) Try and reflash the S2's SD card with a working image. Better yet, find another 4GB+ SD card to test / replace it with.
2) If you're getting exactly the same effect, as others have said buy a BBB over the counter and drop it in. After that its a lot more complicated to diagnose so lets leave it at that for now.

Let me know how you get on.

[dogie]

Thanks Dogie,

What do you think reasonable percentages are for the Diff1#, DiffA# on the HW line?

My S2 has been running for 2 hours and I am at:  2456  0.1358%  0.1506%
Thanks again.

That's fine.

[Zelek Uther]

Sounds like it might be the old problem of a corrupted SD card. Take it out and try to read it on your pc to see if it's still ok.

Ah yes! Of course, I should have thought of that. I did replace the original SD card with a high quality one I bought specially, but it has been running for a long time and I guess corruption can happen.

I think your right.  I had one Bitmain BBB completely fail on me.  Good news is that you can replace it with an over the counter BBB; if that isn't the problem just return the BBB.

Thanks - good to know it's just a standard BBB (if it comes to needing replacement).

Assuming PSU is fine because those AX1200is are rock solid.

1) Try and reflash the S2's SD card with a working image. Better yet, find another 4GB+ SD card to test / replace it with.
2) If you're getting exactly the same effect, as others have said buy a BBB over the counter and drop it in. After that its a lot more complicated to diagnose so lets leave it at that for now.

Let me know how you get on.

Very helpful, thanks dogie (and nice to get official confirmation that the controller is a standard BBB). I'll start troubleshooting with another SD card as suggested.

It's at a remote location (i.e. not at home) so it might take me a while to get access, but I'll report back.

[Zelek Uther]

Zelek,

I know this has nothing to do with your questions but in your post you stated that you have the units in a rack. Is it s server rack?  If so how is the temperature on the units?

I have 6 A2s and a few LTC machines and was thinking about buying a server cabinet from a place down the road but was concerned about the heat disbursement.

RCMco

Yes, I have a number of miners, including my AntMiner S2, in a quiet rack cabinet. I had to for that location as it is situated in a shop (well, a gymnasium) in a mall and needed to be inaudible. The rack cabinet does do a great job of quietening the sound of the miners, I can't hear it above the ambient noise of the mall (e.g. there is a water fountain nearby that makes more noise).

I'd say the main issue with the cabinet I have is that it can't take more than about 5kW of heat. It is designed to house regular IT equipment, rather than bitcoin miners which put out a lot of heat in comparison. Whichever cabinet you are looking at, I'd say the heat is the biggest factor limiting how many miners can fit inside. My cabinet is a UCoustic from Acoustiproducts, and while it is a wonderful cabinet (it really is!) they say on their website that it can handle 7.2kW (see http://www.acoustiproducts.com/en/ucoustic_active.asp), whereas I'm finding a limit at about 5kW*. Basically the cabinet fans just don't push enough air through to cope with it after about 5kW. I know this because I have another cabinet with 2x Spond SP30s, and one of the SP30s doesn't reach it's max speed of 4.5TH/s because it is too hot. If I run just one, it is fine. If I run two, the top one only runs at about 3.9TH/s because the firmware limits the speed of the ASICs to prevent them from overheating (a good thing).

So I'd only recommend a cabinet if reducing noise is a must-have.

FYI I have some videos of both my quiet rack cabinets:
https://bitcointalk.org/index.php?topic=525469.msg7208256#msg7208256
https://bitcointalk.org/index.php?topic=521520.msg8897531#msg8897531

* This would depend on the temperature of the intake air. These cabinets are designed to run in an air-conditioned office (so you can save space by not having a dedicated server room), so they might be able to handle 7.2kW if the intake temperature is say 21C. My cabinets are not operating in air-con however (the gym location gets sun-strike through the clear skylights, so even though there is air-con in the mall it doesn't really keep up in that area and it ends up being higher, like a normal non-air con room temp. The cellar location has no air-con). So it depends on the environment where the cabinet will be installed.

[djroadking]

Well I just might give in and buy an S2 off amazon... Yes or no?

[samsonn25]

Why not the s3 or s5?

[Rabinovitch]

Well I just might give in and buy an S2 off amazon... Yes or no?

No. Since we don't know about any kind of upgrade kit for S2s - no. It is very inefficient in sense of power - here is another "no".

Take S5 instead.

[djroadking]

Well I just might give in and buy an S2 off amazon... Yes or no?

No. Since we don't know about any kind of upgrade kit for S2s - no. It is very inefficient in sense of power - here is another "no".

Take S5 instead.

Power supply stuff. Anyways I decided to hold off and wait until another few paychecks come in so give me about 2 weeks and I'll order a S3+.

[RCMco]

Thanks for the info Zelek.


Over the weekend my 5 year old son stuck a pen inside the grill of one of my S2s and it snapped a blade on the fan. Can't really get too mad at him as he was bringing me a cupcake at the time because he thought I might be hungry.

Any data on replacement fans around?  I know the size but was wondering if there is a preferred aftermarket model?

[AbuGarcia]

http://www.ebay.com/itm/Dell-FOXCONN-PV123812DSPF-01-P-N-NN495-120mm-x-38mm-Fan-/191495555972?pt=LH_DefaultDomain_0&hash=item2c96064b84

These fans work just as good.  It's next to impossible finding a 140mm PWM that can go 3000rpm.  So just use the 120mm size.  The colors of the wires match up with the old ones.  The connector will fit on the mainboard pins, you just need to push them out on the fan connector and rearrange them. Also you need to use an exacto knife or scissor blade to remove one of the notches on the fan connector.
 
To mount them use zip ties, one set for the fan, then another set for the fan grill.  

I've done this for two s2's for all four fans each.   They actually make the s2 run cooler, they are about the same loudness as the 140mm ones.  

[RCMco]

Thanks for the help/link.  Will order a few just in case.

[mewhoyou]

Extranonce subscription

Can anyone share some light if this is possible to enable in S2?

[adaseb]

I won an auction for an S2 for only 0.30BTC plus shipping. Im super excited.

Free Electricity FTW!

I can't believe these cost 8BTC 9 months ago, just wondering did anybody actually ROI ? It looks impossible even if you had free electricity because the most BTC you could of earned was only 8 BTC in total.

[Tupsu]

I won an auction for an S2 for only 0.30BTC plus shipping. Im super excited.

Free Electricity FTW!

I can't believe these cost 8BTC 9 months ago, just wondering did anybody actually ROI ? It looks impossible even if you had free electricity because the most BTC you could of earned was only 8 BTC in total.

Order Details

AntMiner S2 1TH/s Miner Batch 4 × 1  1850 USD ( 3.135 BTC )
AntMiner S2 Coupon 400 USD x 1   -400 USD ( -0.678 BTC )
Shipping  UPS 0  BTC
Order Total: 2.457 BTC

Send Details Date 2014-06-26

[Rabinovitch]

Order Details

AntMiner S2 1TH/s Miner Batch 4 × 1  1850 USD ( 3.135 BTC )
AntMiner S2 Coupon 400 USD x 1   -400 USD ( -0.678 BTC )
Shipping  UPS 0  BTC
Order Total: 2.457 BTC

Send Details Date 2014-06-26

How could you spend this coupon for buying S2?!!.. It was intended only for purchasing S4... 

[Rabinovitch]

Any data on replacement fans around?  I know the size but was wondering if there is a preferred aftermarket model?

Since you need to replace only one fan, you may take a look at this one: http://www.ebay.com/itm/Noctua-NF-A14-industrialPPC-2000-PWM-140mm-2000RPM-31-5-dBA-4-pin-SSO2-/171542597612?pt=LH_DefaultDomain_0&hash=item27f0bc4fec.

Once I tried to decrease a noise produced by S2 and replaced two front fans with this model: http://www.ebay.com/itm/Noctua-NF-A14-PWM-140mm-Premium-Quality-Fan-/281414341027?pt=LH_DefaultDomain_0&hash=item41859a11a3. The temperature of the chips has rised at 2-3 C.

So if you replace only one fan with that industrialPPC, it should be OK, since it can spin at 3000 rpm instead of 1500 rpm that "usual" Noctua NF-A14 PWM can spin at.