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Hey Guys,

Having a little trouble with 2 Antminers S7. So, here is a little background info. I have a bunch of Antminers S5 and S4 that have been running for over a year with out any problems. I am slowly changing them out to S7 Antminers and possible some S9. Anyway, I have purchase 3 brand new S7, never used, factory sealed about a month ago. I have set 2 of them up and I am waiting for a power supply to get the 3rd one up. The two S7 miners were working fine until I decided to move their locations from one outlet to another. One of the Antminers powers up and mines perfectly and the other will not. It powers up fine and I am able to get into the web pages. It will start mining and then stop after 20 seconds. It will only get up to 5.22 GH/s and then stops to nothing. I put it aside for now and started using the 3rd S7 I had sitting around. The 3rd one was also working perfectly until I decided to move that one today and guess what ? The same exact thing happened with this miner. Boots up fine, fans spin, starts mining but doesn't get far and quits. I tried just about everything to get this miner up and running again. I factory defaulted it, I resent the latest Firmware to it and still same issue. I was reading online and saw a post about it being a power supply issue. I have 2 1200 watt power supplies per S7. One 1200 watt feeds 2 hash boards and the other 1200 watt feeds one hash board and the controller board. I don't think the power supplies would cause this as they did work fine at one point. Is it possible I have a bad batch of miners ? Has there been an issue with these hash boards ? Has this happened to anybody else ? I'm stating to think the hash boards got fried somehow. I am very disappointing that this not only happened to one unit, but two units. Any ideas would be greatly appreciated.

Thanks !!! 

Still say it is PSU related since they are ran off of 110v. By and large the s7 and s9 miners do not like running off of multiple PSU's.

You might want to look into Sidehack's How to undervolt/clock the s7. https://bitcointalk.org/index.php?topic=1504228.msg15298837#msg15298837
Can get an s7 down to ~ 800w and still running around 3.7THs. Perfect for your PSU's.

Thank you !! I actually have a BITMAIN APW3-12-1600-B2 but didn't have a 220v outlet where I wanted the miner to live. What I did was moved the miner near my breaker panel and tapped off the panel and got 220v for the BITMAIN PS to test the miner and see if it was because of the power supplies but I still have the same issue. I think I toasted the hash boards. If I did then I will be very disappointed as now I have two S7 with damaged hash boards. Is there any other ideas I can try ? Thanks for the support !!!

What kind of S7 did you scrounge up that it "only" gets up to 5.22GH? The best stock model I know of defaults to I think 4.86TH
I wonder if it was running hot, or if it was a 600MHz model that got cranked to 700MHz and might have damaged the string regulator.

LOl, it's definitely an S7 with 4.73TH/s. It was mining that low because I believe it's screwed up. Well, I think I screwed up one or two of the 3 hashing boards. When it was working, I was getting 4.7TH/s. It never ran hot. I always adjusted fan speed to keep the temps at about 63 or so degrees or lower. Thanks guys !

missed that part entirely <doh!>
Ja. My s7 batch 1 (700mHz) and batch 5 (650mHz) routinely exceed that but all other batches hit closer to the 4.7 to 4.8 mark at stock speeds. God I love those 2. Very hungry but the b1 is normally over 5.6THs and the b5 close behind around 5.4. Amazing and with zero trouble  to-date <knock wood>

Okay, now I think we're both confused.

These were 2 S7s right out of a factory sealed box. Take a look at the screenshots. As you can see, it will not mine. It tries to but everything gets discarded. Strange. LOL, How do I add a pic here ?

You can't and have it directly displayed. Not enough time here and not enough posts.

I *think* you can add just a link to one. Has to be from Imugr and must be the direct web link -- not one formatted for forums, bbs, etc.

No matter what, no s7 from batches after about 5 or 6 are faster than 4.7 or 4.8 THs at stock speeds. So, what speed is reported? (if any) If you can get the Status page of the GUI to display something, what MHz is the speed reported?

700Mhz. I haven't touched it. Left it alone and it came like that from the factory.

http://imgur.com/H4R7ZXX

http://imgur.com/3D5HwOW

Here are the links to some pics of the web interface.


Let me know what you guys think and thanks !!!

1 last option I can think of....

Please update the firmware from the main "System" tab then "Upgrade"

In the Upgrade Page, There is a section called, "Flash new firmware image"  Please UNCHECK, "Keep settings:"

Then upload this 2-fan model  (If 1 fan model, please use the 1-fan model firmware)
https://shop.bitmain.com/files/download/S7-20160523-700M-2fan-4320.tar.gz

Thanks so much for the recommendation. I am extremely scared to update Firmware. I have tried this on the other S7 that had this same issue and it turned into a brick. I am still crying over it  :'( . Anyway tho, at this point, I will try anything. I have an open chat with Bitmain's support and waiting to see what they say about it. I noticed if it's not mining, it will show x.x.x.x where the Hardware Version is. It will only report this when it mines, which is when I turn it on. It tries to mine for a minute or two and then gives up. I also notice when it's trying to mine after power up, the load average on some hash boards goes up to 3.12 or even higher. My working miner's load average hovers at about the 1.0 mark. Do you think my hash board(s) are toast ? Thanks again for all your help !!

First: Give these some time to do their thing. It takes about 2-3 min for the miners to go through all of its warmup cycles. Fans will start/stop and power used will go up/down. I usually don't start checking on a miner until about 5min from power-on to give them time to settle down.

The Hardware Version x.x.x is from the boards not being ready yet or are otherwise unable to talk to the OS or CGminer.

To hopefully un-brick ref https://bitcointalk.org/index.php?topic=1658996.msg16661364#msg16661364
Ya is for the s9 but pretty much the same applies for the s7. Just be sure to give the process several minutes

I have some S7s that do not like to hash at the full 700. Turn em down to 693 and see if that kickstarts it. If that doesnt work just flash the latest firmware. I flashed 90 machines yesterday with the 5/23 firmware with zero issues.

Thanks again guys. This is a screenshot of the miner running for almost 15 minutes. Let me know what you think. I think I am going to try the Firmware. Thanks !!

http://imgur.com/nBPP6kt

Just updated the Firmware. It's still doing the same thing what's picture in the screenshot in the above link. Think im pretty much screwed.

If you are in the USA, you can send the unit to Colorado for repair.  or contact the seller and ask for refund or buyer protection option depends on what service you use.

you can reach the repair center in Denver, Colorado via support@bitmainwarranty.com

Thanks so much for all your help guys. I would like to know why this happened ? Not only to one S7 but 2 of them. I have more S7s and don't even want to use them at this point. Ive had S3, S4 and S5 and never once had a problem like this. Are S7 just really sensitive to the PS you use or there must be a defective batch. I am using server grade power supplies with a total of 2400 watts which should be fine. These are the same power supplies I used for the S5s. The hash boards are getting roughly 600 watts a piece.  I purchased these miners as-is so a return is out of the question. They were brand new, right out of a factory sealed box.  If I do get them repaired, what are the chances this happens again ? I don't know if it's even worth repair with the current Bitcoin difficulty. I might just sell them on eBay as broken. I am really disappointed as these are less then 2 weeks old. Anyway, I am speaking with a Bitmain tech support person now and just waiting the hear what they say.

hello guys please i want to know the best hardware to start mining and there source to get them , i do have all requirements just need a prove start thank you

Ok guys. I figured out what was wrong and I wanted to post what the issue was for anybody else experiencing the same symptoms. It turned out I have a bad hash board. Only one is bad. I removed the boards one by one until the miner was up and running. I am very disappointed however because I have 2 practically brand new miners and each have a bad hash board. I spent hundreds of dollars on these and only got a full week or 2 of mining and now I need to purchase new hash boards because I doubt Bitmain will cover them as I didn't purchase them from their website. I still would like to know why this happened and what's to prevent it from happening again ? Like I said earlier, I have S3, S4, S5 and even S7-LNs miners and never had to replace one single hash board from years of mining. If the S9 units are like this then I will stay away from them as well. I hope Bitmain can see that I obviously have a defective batch as nobody else had issue like this..

Thanks guys for all your help !!!!!

Considering that the s7's have been out of production since shortly after the s9's arrived in spring there is no way that Bitmain would cover it as a warranty issue. Even if bought new from them back then and never used, warranty is only 90-days from you or the original buyer getting it.

My guess is that the bad boards have damage to the 3.3v feed to the PIC and GPIO circuits of the BB. Because all 3 boards get the 3.3v from the same point on the controller If 1 board is shorted it will try to take down the other boards as well.

Let me guess, the boards in each s7's were fed from 2 PSU's? That is when something like this is most likely to happen. When using 2 PSU's always be sure to power the controller last so the 3.3v comes alive after the +12v to all hash boards does.

Did you try moving them back to the outlet where they did work and see if they work again?

The initial description does not scream bad hash board to me, it makes me think that the outlet that you moved them to has bad wiring and is not supplying the power needed to the PSUs.

Yes, 2 power supplies powering up the S7. I always waited a few minutes before powering up the controller. I would power up the hash boards first. I always did this. Never once powered up everything at once. Even when I was using a single 1600 watt Bitmain power supply.

Is there anyway to fix these hash boards myself ? You are right about Bitmain not covering it. I just don't want to spend the $ on repairs and have the exact same thing happen to me again.

Thanks !!

You really need to ask Sidehack about what might be damaged. He did a lot of poking around the s7 while figuring out the undervolting mod he came up with. I assume that if you swap data cable to move the bad board to a previously working port (and good board to port that had bad board) the problem follows the bad board?

As for powering up with a single supply as long as the supply has a single 12v rail - like the Bitmain ones do - by all means do it all at once using the supplies DC on-off jumper. Takes the whole sequencing thing out of the picture. It is supplies that have multiple 12v rails that can be a problem. For those be sure to not have different rails feeding the same board.

Thank you NotFuzzyWarm ! I am keeping away from the multiple power supplies and sticking with the single Bitmain 1600 PSU. What jumper are you referring to  ? I see a removable jumper on green and yellow wire. Is that the jumper ?

Thanks !!

Yes. The yellow/green wires with green wire jumper is the DC output on/off control.

Assuming all PCIe leads are plugged in, best startup is:
Remove jumper (or if is replaced with a little switch like I do, open it)
Plug in psu.
Connect jumper/close switch. DC will turn on.

Using the jumper is best for on/off because it switches the DC output after the voltage is stable giving a very clean and solid on/off.

Awesome !! Thanks so much !