The cap is fried, however most likely it has fried because of a failure of one or both of the BM1384 ASIC chips on the Node. Dependant on the exact mode of failure of the BM1384 the 2V capacitor will have been overvolted causing failure. Measuring across the capacitor resistor should read about 4.7 Ohms (Do allow for resistance of the meter leads by connecting them together before measuring)

So you can try replacing the capacitor but almost certainly one or both of the BM1384 chips will also have failed. Changing them is much more difficult.

Rich

The S5 Hashboard is a simple design, but tricky to troubleshoot & repair because of it's string design often gives a "One Down All Down" result. I will at some point do a Trouble Shooting & Repair thread, but although my understanding of the Board is improving all the time I do not feel qualified to do that yet. I also only have one failed board to play with which is slowing things.

Back to your question it is really too complicated to cover in a few lines, however the first step is to check the voltage across each of the 15 nodes (The capacitor you have just replaced) These should all be about 0.8V, a "faulty" node will be more or less than this, however this is complicated in practice because a fault driven increase or decrease on a node will also result in the converse change spread over the remaining nodes.

Next thing to check is the 14V from the Upconverter at the Top Right of the board, and then check that the 25MHz oscillator Y1 is running.

Bypassing nodes is possible, but only practical if it is one of the upper nodes that has failed, and even then you would need to reduce the 12V supply accordingly.

Bottom line is almost certainly an ASIC or two has failed (The Node voltages will help confirm this) and the only real course of action is to remove & replace. The replacement would have to be taken from another board as that is the only source...


Rich

S5 getting on a bit now in Miner Years & people don't tend to post that theirs is fit and well... 


Rich

Well, I have a minor problem. I added an extra hashboard to one controller, totalling 3 hashboards/controller. All 3 chains are found,no dead chips,no hw errors. But total hashrate is only 1.33 TH. I expected 1.6 TH. All blades are good and with separate controller I get hashrate right. So what could be the cause of the problem? I power it with dps-2000 server psu, so it gets enough juice. And yes power consumption is about 910W from wall, I measured it.

I usually try to solve problems myself but this one goes over my head. Is there any other fw than 20150107 that supports more than two boards. And I'll swap that board to another s5 and see what the hashrate then will be.

Yep, I flashed that same fw and it works perfect. Thanks for Tupsu for mailing link to me.

 I once read this:
 "One other item to consider in making a "4-blade S5 Extreme" miner. The most recent firmware that Bitmain has released will NOT support four blades on a single controller. If that doesn't bother you then feel free to proceed. I personally would keep it as two separate miners. I think Ethernet switches are pretty cheap. A used one couldn't even cost $10, could it?"

And there was link to that fw that I first tried. It worked, but not so well  .

Edit: after 20h average hashrate is 1.73TH. So far so good. And temps are much lower too.

Every now and then, I will lose half or all of my hashing power on the S5. Powering off and on the unit will fix it but simply rebooting from the command line or web interface (both are working fine) will not. The status line for the blades shows all 'o's. Is there a way to bring it back to life remotely or am I going to have to work out some kind of remote power control??

Edit: Dropping the clock and restarting brought half of the hashing back. The other board is all Xs now so at least that's getting somewhere.

Edit2: Another reboot and all 'o's again but my hashrate is still around 1/2 what it should be. Think I'll have to rig up an R-Pi for remote power switching.

i've created a script just to soft restart the miner overtime if it drops below a certain hashrate. you can set the minimum hashrate in "minhash" (80000 = 800GH/s).

ssh into the miner and save it in theconfig folder. any name you want. example hashcheck. then chmod 755 hashcheck.

to run the script, enter "nohupconfig/hashcheck &". this will allow the script to run after you exit from ssh

to view the log enter yourmineraddress/hashcheck.txt in your browser.