Hacking Bitmain Antminers (S7 & S9) because man a lot of these break......

[mkptr]

Hey,


Sent you a pm.

[MinerMEDIC]

Speaking of nifty tools here is a video of a S9 hash board booting up and starting to hash normally. This shows a nifty little 2400W ammeter that I built with parts off of eBay. If I had a bigger power supply I could've tested all three at the same time( of course I've never actually owned three working boards, lol). Consequently this is pretty much the only way to prove beyond a doubt that your power supply is fully functional(I Actually built a dummy load out of car head lights be used for this exact purpose).
https://youtu.be/4GV7fyXKBdA

[Hazzard]

You can order those chips on alibaba. Perhaps even aliexpress.

Could you replace said chip?

If so, just replace, add thermal paste and heatsink, should be good to go.

Pardon if my suggestion isn't the best, just trying to help. Know a good deal about computer hardware but this isn't my expertise.

What is the name of the chip we need to purchase?
Can you post a link to an example?


I too am having issues with a miner that kills my PSUs after only half an hour.

[lightfoot]

Shuts down the power supply? Is it an S7 or 9?

C

[the_electronrancher]

You can order those chips on alibaba. Perhaps even aliexpress.

Could you replace said chip?

If so, just replace, add thermal paste and heatsink, should be good to go.

Pardon if my suggestion isn't the best, just trying to help. Know a good deal about computer hardware but this isn't my expertise.

What is the name of the chip we need to purchase?
Can you post a link to an example?


I too am having issues with a miner that kills my PSUs after only half an hour.

I can give you a link for a Taobao seller advertising fake antminer chips.  No joke - he is openly selling counterfeits that other sellers will in turn resell to us.  Seeing that kind of turned me off to looking for a source other than bitmain.

[Dave64]

I have a 2 month old S9 that lost a chip, lightfoot has it and posted a pic of it above, since I cannot get a replacement chip, I am considering paying him to remove the 62 working chips so I can sell them for $100ea. Would there be any interest in this? I know if someone was offering to sell me a working chip for $100, I would jump on it.

[numnutz2009]

I have a 2 month old S9 that lost a chip, lightfoot has it and posted a pic of it above, since I cannot get a replacement chip, I am considering paying him to remove the 62 working chips so I can sell them for $100ea. Would there be any interest in this? I know if someone was offering to sell me a working chip for $100, I would jump on it.

lol u think a working board broken down is worth $6200?? i guess technically $6100 since one chip is bad but either way have u lost ur damn mind man??

1 the miner is only 2 months old so repairs are covered under warranty

2 ur hopin to price gouge worse than bitmain does and u somehow think thats ok to do lol. r u payin the nice guy that did all the work $5k of that $6100?? i highly doubt it.

ne one that thinks 1 miner with 3 boards is worth $18k+ is long past the point of return. jesus!

[Dave64]

Bitmain was requiring me to send the whole miner to China and other people claim it takes at least 8 weeks to get it back,  plus the chip is bad because of my own fault and really shouldn't be under warranty.
Like I said before, I would be more than happy to pay you $100 for a working chip if you want to scrap your board so I don't have to. Its not gouging when people are willing to pay it happily.

[HagssFIN]

Bitmain was requiring me to send the whole miner to China and other people claim it takes at least 8 weeks to get it back,  plus the chip is bad because of my own fault and really shouldn't be under warranty.
Like I said before, I would be more than happy to pay you $100 for a working chip if you want to scrap your board so I don't have to. Its not gouging when people are willing to pay it happily.

I think a good option for you is to contact MyRig (previously known as BitmainWarranty).
They do out-of-warranty paid repair service for Antminers.

Contact them and figure out your issue and the repair service process.

https://myrig.com/contacts/

[numnutz2009]

Bitmain was requiring me to send the whole miner to China and other people claim it takes at least 8 weeks to get it back,  plus the chip is bad because of my own fault and really shouldn't be under warranty.
Like I said before, I would be more than happy to pay you $100 for a working chip if you want to scrap your board so I don't have to. Its not gouging when people are willing to pay it happily.

bitmain has an option to send the board to a repair place in ca for in warranty repairs. even if you have to send ur whole miner in its far less than $100 if ur inside the us. as for people being happily willing to pay it...im not so sure about that one lol. bitmain warranty will repair a board for $200 or so shipped. they will charge $200 even if the chip is provided. i can remove chips from the boards if needed but i rather not price gouge the hell outta people for $100 per chip. its not right and the markup is insane especially since theres no way to guarantee that the chips removed will function properly.

[Dave64]

Bitmain offered no inside USA help, even after I offered to pay for the repair, they still wanted me to ship the whole unit back to China

[HagssFIN]

MyRig is a separate company and not a part of Bitmain.

Did you ask them also or just Bitmain only?

[Dave64]

Just bitmain, after getting scammed by syan and almost by a few others, I find it hard to trust anyone. I took a chance with lightfoot and he is a straight up guy, but has no chips to help me get my board going.

[HagssFIN]

MyRig (previously known as BitmainWarranty) is legit, I have had few paid repairs done at their facility and you can also ask philipma1957 who has also done business with them.

[ccgllc]

MyRig (previously known as BitmainWarranty) is legit, I have had few paid repairs done at their facility and you can also ask philipma1957 who has also done business with them.

I've also done business with them:  I sent them 5 bad older fixed-frequency boards.  They managed to fix 2 of them (for a reasonable fee, but it took 2+ month) and sent the other 3 back a bit worse-for-the-wear without charge.

Currently they have (2) newer boards and a controller that I screwed up loading firmware on (somehow got out of sync while doing 8 at a time and managed to get the reflashing process to start twice on a single board).  They have had them since December 12th.  Communication feels spotty - I ask weekly how its going and unfortunately don't always get a reply.

These last 2 boards were actually only a few weeks old, so under warranty, but Bitmain insisted I send the entire miner for each - meaning I would have (4) otherwise fully functional hash boards offline for a couple of months.  Instead I opted to just pay the repair fee to BItmainWarranty.

[the_electronrancher]

I'll sell you a chip for $100.

Problem is, it's about 0.4mm pitch blind mount and not likely to be seated successfully without a split vision system.

Also, fails are often more than one chip.  Haven't read the most recent parts of this thread, but the fails I've seen cascaded over multiple tiers of chips.

I'm not trying to talk you out of it, but I don't want complaints that my chip is bad just because you can't place it.

Or, if you're sure it's only one chip, have the whole top tier pulled off and use one of those.  If you don't adjust the pic you'll be running at 50mV overvolt for the remaining tiers..  not that big a deal

[jfedyks]

Meantime just fixed a pair of S7's that came in the door. Both had pretty burned plugs:

https://i.imgur.com/pnDyyAy.jpg

And after repairs we have nice new nickel plugs...

https://i.imgur.com/Sp8mtls.jpg

The trick to doing a proper plug replacement is as follows:
1) preheat: You have to get the board hot enough to allow the solder to be molten for a bit, both to get the old plug off and to remove the old solder.
2) rosin solder: Has a slightly lower melting point than ROHS crap: Use it to alloy the solder on the pins, reduces the temp a lot
3) Air heat: Use to heat all the pins at once allowing you to easily remove the plugs.

Then clean up the pads, flux the new plug, put in, warm up, and solder. A good preheater can make the difference. Trying to do it without one will result in damaged pads and Vias, which will not be able to conduct the proper amount of current.

First, thank you for this thread it's invaluable! I recently powered down my S7 for routine maintenance and cleaning and noticed that my power connectors were fused to the white PCB headers (very similar to your photo) on 2 out of 3 boards.  It was hashing fine when I shut it down and probably would have kept running if I wasn't so paranoid. I was using an old X11 board (I think v4 or v6) and there seems to be varying opinions on whether it was a surge or a if the opposite wires became exposed and "arced" (I am very new to comprehending electricity)?

I found a local guy who does soldering and he's agreed to replace the 3 headers on each board for $70 USD total ($35/board) if I provided the components.  I have found and ordered a bunch from this site but I am uncertain if they will definitely work. https://www.moddiy.com/products/6%252dPin-Graphics-Card-PCIe-Male-Header-Connector-%252d-90%25-Angled-%252d-Black.html Could you please verify that this part is an acceptable replacement.  Also about those nickel ones, would you mind sharing where you ordered from?  And do you think the price quote I received is a fair one?  (I will likely refer him to this post for your step by step instructions) If I continue down this path I may perhaps need his services again in the future.  And tbh after reading this post I'm starting to think it may be time to try my hand at soldering.

[the_electronrancher]

They are called molex mini fit jr

They are a couple bucks each from mouser or digikey, or maybe $1.00 more to upgrade to the gold finish.

The ones you linked will work fine

[lightfoot]

Meantime been busy here working on things. Here's an interesting picture: The S9 in question is dead, and oddly enough does not respond. Checking clock signals with the scope shows clock to the end of the board but not on the other side. So I pulled the back sinks and checked. Sure enough the three test points on the bottom of the board were ok, the top ones were dead.

Pulled the heat sinks, cleared off the crud, and we see this on the third chip, bottom side:



If you look carefully on the right side of the chip you see the solder doesn't look right. What happened is either a cold solder joint from the glue factory (Bitmain) or more likely the chip overheated and melted the solder out. Either way no contact, not going to work.

Off to reflow-world....

[Dibblah]

Just in case anyone is wondering, yes, it is possible to reflow a whole board as a last ditch attempt for boards where the source of the fault is extremely tricksy.

 I don't have a proper oven which can cope with the maaaaaasive thermal mass of all of the heatsinks, so this puts the board *way* outside of the reflow parameters (it takes about 15 minutes to get up to reflow).

... Take off the electrolytics and the power connectors, clean board (I use isopropyl dip), apply thinned down flux to the topside only, ensure that you are heating on a solid surface.

On a completely unrelated note, the black thermal adhesive copes remarkably well with heat. The white stuff... Not so much. Completely degrades and a slight touch will knock off the heatsink. So, I now have a completely bare of heatsinks board and am desperately trying to think of a way to properly heatsink it. I may just end up oil bathing the damn thing (it's a 54 chip board, so there are no non-SMD electrolytics).

If you leave the connectors on, they will survive (foil wrapped) but look unhealthily yellowed. Subtext: Don't do this, there are *far* better ways to spend your money and time.