There is of course also the option of running p2pool.org: Highly distributed, pays out new coins, pretty anonymous, and you can elect 0% to the pool development if you really want to. Also pays out all tx fees.

Flip it over, other side same area. The FETs are small square things with 4 pins on one side and what look like 4 on the other (ground plane).

So the unit starts up, then shuts down that power supply once it hits a certain spot in the boot sequence? If so it means when the PS tries to buck by turning on the shorted FET takes it down. One interesting thing about S9's is that they put a heat sink on the other side of the board for them, which indicates they are running those supplies harder than the S7's....

C

Imgur is good for uploading then post the URL of the image.

What I'm looking for is a close up of the FETs to see if there is any bulging or discoloration on them. I'm curious to see if the addition of a second FET on the low side (which has to switch at a higher frequency) has caused the typical capacitance ringing problem where the FETs can't switch quickly enough and burn out even though you would think 2 fets are better than one....

C

It's the 25mhz crystal that is just barely under one of the heat sinks north of the coil. That I believe is what provides the master xclock to the chips; they put in a whole bunch of pads for secondary clocks but I think they drive each chip's clock from the previous one in a line. No clock=no chip running.

There's usually 3 things each miner needs:
Power
Clock
Signal

Get those three and working chips and you should be underway in some capacity. We have power, next thing to check is clock.

Oddly enough I wonder if sub-standard crystal chips are the cause of low temp failures. They should run down below 0c, but maybe they don't.

C

Interesting. DC-DC converters are fine, so it's got to be the crystal. I have a board like that here, I'll try swapping the crystal and see what happens.

C

Naah. We built the Internet over AT&T Connect (which is what the corps were pushing) and when Internet turns into AOL again, or Cable TV we will simply build a new one and hook that into the rest of the world.

I still have my UUCICO system ready to go. No biggie. In the meantime you Europeans, Asians, and whatever else (Kiwi's?) will continue to innovate and rule. Maybe we can buy a state full of slaves to hand-calculate bitcoin hashes because we can.....

C

Use caution Torque. A lot of this is pure chance and us being in the right place at the right time and taking a chance. I've seen a number of people think that because they were in the right place at the right time it was due to their sooper skillz and not chance. Then they think they are super smart and lose everything an investment or two down the road because they know how to pick (stocks, companies, cars, collectibles, etc).

It's easy and fun to look at things in hindsight, but know that you don't bet the farm on every opportunity because most do not pan out. This one did....

They should love that. Initial value=0 means everything is taxable as a gain....

Darn! If it's a dead short please take pictures of the FETs on the board (the things next to the little transformer). I want to see what they look like when they cut-through, this is the first report I've heard of a dead short.

Note: If the S9 is out of warranty and shuts down the power supply I can fix this :-) But since yours is in-warranty (what is the warranty these days? 1y or 90d) you should contact Bitmain for a swap.

C

Hm. When did it fail, how did you know, and was there any error messages or beeping to note?

C

That's a lot better than "be ready for us to steal all your money"....

Nice! I just picked up a pair of X1 Carbons myself for work. Damn near indestructible and I love the little nipple/trackpoint.

C

Not trying to shill LTC per se, more of an observation on the overall insanity in the market. Like a cannon ball rolling around on the deck of a pirate ship; the money is just sloshing around.

But Point noted and taken.

Meantime why isn't Bitcoin DOING ANYTHING? This is the most bored I have been all day....

C

Using litecoin at an ATM I get withdrawls and money within like 3 minutes.

Bitcoin takes closer to half an hour. So who has set up Vegas hookers with a litecoin based payment app?

Seriously: You could pay an address, add a tip, and the coins would be split between the hooker, pimp, and driver based upon mutually agreed upon rates signed by private keys held by all parties. That way you the john would know the appropriate money is going to all parties based upon agreed-on ratios.

Hm.................

So.... Antminers...

As the warranties expire on these things and they still break I figured it was time to do some analysis. To that end I'll open up a thread this weekend on hacking them, along the lines of my other threads (information is free, skills are paid for). But some basic thoughts:

1) There is a reason the S9's fail.
2) S7's are still banging along and worthy of repair

The basic design of an Antminer is surprisingly simple: Instead of powering each chip or die individually with a DC-DC, they put the dies in series strings and run them right off the 12v supply with a single boost-buck to control voltage. This is clever because the buck converter doesn't have to step the voltage down from 12 to .8 volts (requiring a high frequency shift on the +12 rail with a very sharp cut-off) instead it's more like 12v to 11v or so (which being only a 1v drop is 18 times more efficient than going to .8v or so). It does however mean that if a single die goes bad a string dies or more likely a zipper effect happens that takes out all 15 or so chips in the string, but that's another issue.

Trimming the power voltage can be done either by a resistive stepper (S7) or via a PIC changing frequencies (S9). Either was not that complicated.

Clocking is provided by the usual 25mhz clock crystal. So when an S7 or S9 fails the key places to look are either the power system or the clocking system. Now to find out which one of these fails in the cold, time to find the fridge!

I'd recommend just getting a spare. Even if you do replace the parts, would you trust it to not have another short that blows out your mining boards?

C

Either one would be fine, there is far less than a 1 ohm difference on the inductor.

That said, if you want to freeze a miner *then* check the voltage that could be a neat data point. I've been split on the cold temp not starting thing; either it's a temp sensor on the DC-DC converter flagging low and keeping the osc from firing, or it's a chip that loses connection with the board when cold. If there is no voltage on a board when cold but voltage when warm we have identified the problem that kills R4's and S7's and probably S9's.

Neat, hm?

Morning! $16,800 bitcoin and 300 litecoin is a more-than-nice thing to wake up to. Not bad, let's see where it goes from here....

Still thinking. If banks are a club that doesn't like new members, is Bitcoin just another club? Do we drive Lambos on the golf course instead of little battery golf carts?

No it's not a fan issue. The chips have just been baked.

C

I know, this is like a mini wall for litecoin peeps.

HODL!

Oh wait, Litecoin is the coin for spending. SPENDL!