Topic: Bitmain's Released Antminer S9, World's First 16nm Miner Ready to Order - page 142. (Read 531178 times)

OK thanks for that. Yeah, I'll have to install aback-up heaters, no way around it.

YES!
For one you risk the large caps being damaged by the freezing. And then there are thermal stresses on soldered connections... Not so much 'making them come loose', more like it causing the solder to start crystallizing. Lead-free solder has enough of that issue at normal temps and deep cold makes it worse.

As a side note: Eliminating solder problems such as crystallization, whiskers/dendrite growth, and a few other things is why alloys containing lead were used in the first place. To-date, NOTHING has been found to take the place of having lead in the mix. Lead-free solder alloys have gotten better but will never be as good when it comes to reliability. Just the nature of the beast.
 
Install heaters to keep above 0C, preferably keep above 10C and you will be fine. Of course that means having vents with louvers that can be closed to keep the heat in when needed.

Before starting I highly suggest taking them up to around 15-20C for at least 15min or more before firing them up.

..Just spamming here lately I am..

So I got another question 

I am thinking about building an S9 farm in a shipping container. Yes, I know its been done before, its dumb, risky, etc etc.. When the container is shut down temporarily in the winter and the damn thing goes to -20 deg C or even -30 deg C (gets this cold in Canada), will the S9's likely be damaged? I mean, clearly thermal cycling is a problem due to stresses causing things to come loose, but will this temperature alone do harm? My plan would be to not start up the S9's until I have first warmed them up again to 0+ deg C.

OK thanks for this info.. oopsies 

Thanks for the detailed reply, love learning about this stuff. I almost feel like going back to school, mechanical engineering now seems so boring.

Thank you for the info guys, I very much appreciate it! 

I'm not saying that all failures are due to heat, just implying that, imo, the larger portion are operator controllable issues (i.e., overheating, dirt, etc.) and not the "fault" of Bitmain.
With most manufactures suggested temps of 65-75F, I can't think of anyone that runs an efficient setup that's over 81F (even Dell, who has the hottest "highest temps", never suggest higher than "lower 80s"). 

re: removing the epoxy
Your mention of scraping got me thinking. Not heat - use canned cold-spray or LN2 if ya got it. Make brittle and should chip off nicely. Epoxies made to take heat usually do not like deep cold and embrittle easily, comes with the turf of what is intended for. Hmm....

If in North America talk to BitmainWarranty in Colorado about it. Also have several locations in other parts of the world as well. https://bitmainwarranty.com

From a power electronics design view, having a temp sensor on the die is the best and most accurate thing to do. That said, with so many chips in these I wonder if there is way to just have the miner look at a different chip? Heck, all chips talk over a single serial bus so should just be a matter of reassigning which to take data from. Problem solved.

As for removing the chips... Check the s7 threads and things dealing with sidehacks 2Pac stick and upcoming Pod miners.

Assuming Bitmain did the same thing with the s9/T9 (looks like it) then fuggitaboutit. If ya know which chip to attack, maybe but it is a risky process worsened but another design point: They made damn sure it would be very hard for the heat sinks to get knocked off buy using a very tough thermal epoxy to bond the topside heatsink to the chip.

A heat gun to applied to the heatsink will soften it enough to pull it off. So far so good. Then you see that when assembled the epoxy has flowed around the outside of the chip itself and so far the normal solvents will not touch it.

Design plus for mechanics and increasing thermal contact area a bit. Con is near impossible to replace a chip without risking damage to the board.

edit: Just saw Fanatic's post above ^^ Bet reflowing the new chip on is fun with the fine lead pitch...
Cool but still would rather sent to CO. $14.95 to ship them a board and that is with it insured for $450 in case it takes a wander.

You would still pay out the ass for shipping + repair. Its the same thing as repairing any other out of warranty board, they arent gonna give you a discount just because you identified the issue for them.

I have removed and replaced chips on an S9 board. You can remove them using long tweezers and a heat gun. The trick is to heat up the larger top heatsinks and use the twwzers to roll the heatsink back and forth, dont just yank on it. Then remove the bottom heatsink in the same manner. If you do this backwards and heat up the smaller heatsink first, when you go to remove the larger heatsink you will yank the chip right off the board. You can heat up the chip a bit and use a razor to scrape off the black goop. Then simply heat up the chip ( around 400-450 f on the heat gun ), pinch it from the sides with the tweezers and slightly wiggle until it pops off, keeping heat applied the whole time. Be very careful with the heat and tweezers as there are many small components you can heat up and knock out of place without even realizing it.

@Bitmain, would you guys be willing to offer an out of warranty repair service for this dead temp sensor chip issue? Even if it costs us $50 it would still be better than a dead ~$300 blade.

Good point. But sometimes it's not the heat that kills them cause we've had board die in the middle of the North Canada winter. All it takes is one or two traces to become undone due to poor sodder or lack of sufficient sodder and bam, chip is offline and bam temp sensor is offline and bam blade is entirely offline. Also according to bitmain specs these are supposed to be able to handle fairly high intake temps - ie a traditional data center environment. I think the reality is a pure and simple ugly truth which is that Bitmain obviously cut corners on design and build quality to wide their profit margins as well as make the miners ore affordable of us miners. I would honestly pay a bit more for a rock solid design implementation and especially one that is user serviceable to a larger degree.

-update- has anyone attempted to remove the chips off of an S9 board? I'm wondering what kind of specialized equipment we'd need.

And how many of those (percentage-wise) are in a properly ventilated area that's always under 77F?  

Oh crap, that's the worst case scenario. Dammit Bitmain why you go so cheap on the design/build quality? Do they not realize that if the miner dies out of warranty they are just basically screwing their customers out of ROI. Should these things not be built well enough/smart enough that they will last more than 6 months before killing themselves.

Thank you.  Appreciated.

https://www.okcoin.com/api/v1/ticker.do?symbol=btc_usd

I caught them on this months ago

they own hashnest and were posting  btc way higher  then they were on the s-9 page they fixed it.  If you go back on this thread I have screenshots that they did this.

Thanks, Internet Tough Guy.   Now I do not have to have my question buried by your inane comments.

I will ask again.   BITMAIN, how do you calculate the US$ to BTC exchange price on your site.   I see it move, so it is a derivative of some index but what one?   It seems to be $50-100 below most exchanges in the last few days.

Nope.
Ignore now active.