Hacking KNC Titan / Jupiter / Neptune miners back to life. Why not?

[lightfoot]

Saw that. Oddly enough the Titan motherboard with some small fixes would be a pretty good place to build a 800mh per cube sort of device. But that's probably not going to happen.

[1715452619]

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[LongAndShort]

Ok, not directly about fixing Titans, but I figured this group would get a nice laugh out of this:
 https://webcache.googleusercontent.com/search?q=cache:MkMLMXxZkQEJ:https://www.cryptocoinsnews.com/knc-miner-returns-improved-mining-product-sale/+&cd=2&hl=en&ct=clnk&gl=us

Disappeared pretty quick, seems familiar...

I've dealt with the owner of that outlet and i have to say he is a shifty man indeed. I would not trust anything that comes out of that website, not even the time. Good laugh tho yeah.

I'm referring to cryptocoins news

[lightfoot]

Meantime back to cooking over a hot oven. Or rework rig. Whatever. :-)

Two more cubes in for repair, looking at them with interest. One had the normal blown drivers, fixed, testing at low speeds tonight for errors, then will ramp it up tomorrow. The second board is odd however. It doesn't crash a Titan controller board with Pi (man these things are so much slower than BB's) but it does fail to respond to PSU Spi requests with the power bus off. Might be a damaged supply screwing up the SPI bus, might be something else. Will review.

[XXXJAYXXX]

Noticed there seems to be a few people on this thread who may be interested in some replacement parts for the KNC Neptune..  I have a few fully functional cubes for sale if anyone here is interested!  Check the thread here...  https://bitcointalk.org/index.php?topic=1923994.0

Thanks for looking!
J

[lightfoot]

So more repairs coming in and I'm seeing something interesting on a few of the cubes.

Apparently someone else is trying to replace the power plugs. That's great, but these plugs are burning out as well and after looking at it I see the problem:

It looks like they are being taken off with a very hot iron without pre-heat. Do-able perhaps, but the problem is that much heat on the bottom is de-laminating the lowest layer of the board; breaking off the pads and causing the lower plane to be powered off the top plane through the vias. Not good, more heat.

More of an issue; the new plugs are being soldered on without warming the whole board, so the solder joints wind up being cold-soldered in the midde of the board. This causes resistance which is causing a lot of heat and baking the pins.

I recommend snipping the neutral pins first, then warming the whole board to around 150c as measured at the board with an IR thermometer first, then tinning the leads with rosin/lead solder, then removing the pins one at a time. With the top three off the bottom three can come off as a set when you tin them (which lowers the melting point of the solder from the very high ROHS levels to a more rational level) at which point you can remove the solder with wicking, test fit the new connector, then put some flux on the new connector pins, put it in, take it off the pre-heater and quickly solder the pins from the bottom. Then put it back on pre-heat, and check to make sure all six pins have solder when viewed from the top.

I can post pics if anyone is interested, but this is important. If the ground leads ever fail or go high resistance the board is destroyed by the resulting voltage differential between the chip hotel supplies from the ground on the controller board and the current demands from the hashing engines. It wrecks the chip and is the only thing so far I can't repair.

C

[lightfoot]

Fixed another 7 boards. This came from a guy that had heat sinks on all of the power supplies, the sinks do allow more power to be pulled but in this case he literally baked off the high side FETs on the supplies. Fortunately he included a bag of supplies, however failures included shorted supply controller chips, and just a general 2 day mess repairing the boards. However I did get 7 fixed, one was fine, one was totally shot.

Today I am working on another three that look like rejects from someone else's attempt to fix boards. Hint: A soldering iron alone will not take off a power supply and ripping up the vias is not impressive. I'm focusing on one board; the drivers were blown and one of the supplies shorted the control pin to 12v. This blew out every single supply on the board, I have pulled up and replaced five of them so far. This is, to be honest, insane.

Oh well. Forunately I have a supply of Titan boards to raid for supplies. Still a mess...

C

[lightfoot]

At last. Everything has been fixed, all the little boxes of repaired miners have gone out USPS Priority Mail, and I can take a break. Figured out how to fix MAT miner controllers as well; they run a version of Ubuntu that is similar to the installs for Beaglebones. So with a bit of work it's possible to get those un-wedged as well.

If you have anything broken, let me know. Should be a more quiet weekend, maybe I'll mow the lawn and things...

[LongAndShort]

At last. Everything has been fixed, all the little boxes of repaired miners have gone out USPS Priority Mail, and I can take a break. Figured out how to fix MAT miner controllers as well; they run a version of Ubuntu that is similar to the installs for Beaglebones. So with a bit of work it's possible to get those un-wedged as well.

If you have anything broken, let me know. Should be a more quiet weekend, maybe I'll mow the lawn and things...

HAHA, good on you mate. You are doing a great thing. Keep it up.

[lightfoot]

Update: The latest version of my beagleboneblack code is uploaded and now just needs a 4gb SD card or bigger to run:

https://www.dropbox.com/s/vfks74mxqlrfyf9/knc-lightfoot%204gb%20version.7z?dl=0

I also updated the link on post #2, that is where I keep all my links and hints.

[Searing]

Mine has been running solid since the .img file was uploaded. I truncated the largest unformatted space on it. I ended up with about 4.2gb of space taken up on a sd card. I burnt it to the sd card using win32 disk manager and started the controller with cubes i knew worked in it and it hasn't failed me yet. I can do all the things i used to on the original. ssh in and bring up the miner screen ect ect.

Maybe try reflashing it to the sd card or even truncating the largest unformated space on the lightfoots original .img file again.

Also try just using one cube at a time. I say that because i have a cube or two that i plug in and it basically wrecks the whole system. Nothing posts at all however, if i unplug it from the controller or from the cube directly (the controller cable not the power) everything works fine again. (did you find a solution or cause to that lightfoot)

I will play with those after my vacation i didnt have chance to play with it longer. All my cubes run perfectly fine. I bought 8 saturns/jupiters to tinker with controllers so im not in hurry, those will be my backups or to split sets or i will just sell them.

One thing I noticed a few days ago was that none of the pages were working. I was wondering what the hell was going on, then realized I forgot to turn on javascript on the page....

Everything worked fine. I think the process could theoretically hang, but the miners would keep mining and a simple reboot would fix it. So far though it's been dead solid reliable on the Neptune hardware.

C

Yup, rock solid and still faster then the Pi. They really muist not have been able to source many bbb at the time of the titan. Probably due to the neptune

Knc techs at the time said a bbb cost 40% more also.

[lightfoot]

Knc techs at the time said a bbb cost 40% more also.

Possibly, however they do seem to blow up a lot and take things out. Haven't seen a BBB fail yet. And with the glut of Neptunes out there it makes sense to take a bbb and run my code on it (free. whee free and all that).

But running a Pi takes forever. I'd consider porting the code to new models of Pi's but that would be a lot of work for a solution that's still slower than a BB.

C

[lightfoot]

Another day, more work. Titans keep on coming in, I've gotten to the point where swapping the plugs is quite do-able, and even the shorts on pin 8 (once a sure dead cube) are fix-able. Glad to see they keep on running, if you need something fixed let me know!

[Searing]

Another day, more work. Titans keep on coming in, I've gotten to the point where swapping the plugs is quite do-able, and even the shorts on pin 8 (once a sure dead cube) are fix-able. Glad to see they keep on running if you need something fixed let me know!

Heh, who'd a thunk in Jan/Feb 2017 at $4.15 LTC or whatever KNC Titans now at 50 bucks an LTC would be making below on

www.litecoinpool.org (used the calc for that site ..no fee 105% payout)

www.litecoinpool.org/calc

profits at $50 LTC at 10c kwh and current difficulty w/o elec considered, a 300mh KNC Titan with Gen Tarkin's Energy Saver setup for 1,250 watts.


24 hours   0.63360352 LTC   31.68 USD   2.94 USD   28.74 USD
7 days   4.43522461 LTC   221.76 USD   20.58 USD   201.18 USD
30 days   19.00810547 LTC   950.41 USD   88.20 USD   862.21 USD

sheesh....you are probably gonna get more busy lightfoot

[lightfoot]

profits at $50 LTC at 10c kwh and current difficulty w/o elec considered, a 300mh KNC Titan with Gen Tarkin's Energy Saver setup for 1,250 watts.


24 hours   0.63360352 LTC   31.68 USD   2.94 USD   28.74 USD
7 days   4.43522461 LTC   221.76 USD   20.58 USD   201.18 USD
30 days   19.00810547 LTC   950.41 USD   88.20 USD   862.21 USD

sheesh....you are probably gonna get more busy lightfoot

I know. I just fixed three more today, the Post Office is going to send me a Christmas card or something.

But these are problems I can deal with. Keep them running at about 1,000mhz (~70mh) total and they run pretty happily.

[lightfoot]

Well, there's always something new. Got two cubes in today for repair. One had a burned plug (fixed, I need to order another box of plugs) with all four dies now working. The second one was weird: The user said it would start mining then shut down the whole contoller within a new minutes. So I hooked it up, put a good heat sink on it, and took a look.

Interesting one. Very, very interesting. Yes, it does come up on four dies (one supply is bad on die 1) and yes it does crash the controller and in one case shut down my power supply. Never seen this one.

Did some work on it. Die 1 is bad. It works, but it's still bad, what happened is that it overheated and damaged both its power supply and the rest of the board to some extent. In this case, when it comes up it goes into thermal runaway as it heats up, ultimately shorting the supplies and the board. You can see the burning on the back of the board, it got very hot.

Turning it off clears that but the other three dies also run very hot. After experimenting for a bit and doing a reflow I found a solution: Run the remaining three dies at a much lower voltage. Running dies 2,3,4 at -.0806 at 275mhz gives you a cube that runs at 57mh while running at 42c in a box with the original style fan. That's a pretty good running cube and about what you should expect from a cube normally. So that's fixed as well.

Never know what you will run into in this business....

[Searing]

Well, there's always something new. Got two cubes in today for repair. One had a burned plug (fixed, I need to order another box of plugs) with all four dies now working. The second one was weird: The user said it would start mining then shut down the whole contoller within a new minutes. So I hooked it up, put a good heat sink on it, and took a look.

Interesting one. Very, very interesting. Yes, it does come up on four dies (one supply is bad on die 1) and yes it does crash the controller and in one case shut down my power supply. Never seen this one.

Did some work on it. Die 1 is bad. It works, but it's still bad, what happened is that it overheated and damaged both its power supply and the rest of the board to some extent. In this case, when it comes up it goes into thermal runaway as it heats up, ultimately shorting the supplies and the board. You can see the burning on the back of the board, it got very hot.

Turning it off clears that but the other three dies also run very hot. After experimenting for a bit and doing a reflow I found a solution: Run the remaining three dies at a much lower voltage. Running dies 2,3,4 at -.0806 at 275mhz gives you a cube that runs at 57mh while running at 42c in a box with the original style fan. That's a pretty good running cube and about what you should expect from a cube normally. So that's fixed as well.

Never know what you will run into in this business....

Just a note..a maxumark bracket (get rid of u shaped knc kludge heatsink) and putting on the individual heatsink option on each dc/dc chip

might further reduce his heat....the noctura fan mod at 3000 rpm (20% more noise) vs standard 1500 rpm knc also may help

anyway if you wanted to extend the life of a cube the 10 buck maxumark bracket and heatsinks direct on dc/dc's and maybe the fan is how

I'd go..just a thought to pass on to the guy.

With the above mods my temps on my dc/dc's went down 10-15c on ALL modified dies, this is with the maxumark bracket and the noctura 3000 rpm fan mods.

So my miners in the basement in the summer NOW run at the heat they used to run w/o any mod the previous Winter! 10c-15c is a big deal in real heat output

no more shutting down titans on 90F plus days now....it cut me that much slack in heat etc

brad

[BitcoinPappi]

Freshly repaired 3 cubes by the one and only lightfoot.  Hashes at 170 MH/s feel free to ping me an offer.  Would like to let them go instead of putting them in storage.  If not I might have to find some extra space to run them

[alucard20724]

Well, there's always something new. Got two cubes in today for repair. One had a burned plug (fixed, I need to order another box of plugs) with all four dies now working. The second one was weird: The user said it would start mining then shut down the whole contoller within a new minutes. So I hooked it up, put a good heat sink on it, and took a look.

Interesting one. Very, very interesting. Yes, it does come up on four dies (one supply is bad on die 1) and yes it does crash the controller and in one case shut down my power supply. Never seen this one.

Did some work on it. Die 1 is bad. It works, but it's still bad, what happened is that it overheated and damaged both its power supply and the rest of the board to some extent. In this case, when it comes up it goes into thermal runaway as it heats up, ultimately shorting the supplies and the board. You can see the burning on the back of the board, it got very hot.

Turning it off clears that but the other three dies also run very hot. After experimenting for a bit and doing a reflow I found a solution: Run the remaining three dies at a much lower voltage. Running dies 2,3,4 at -.0806 at 275mhz gives you a cube that runs at 57mh while running at 42c in a box with the original style fan. That's a pretty good running cube and about what you should expect from a cube normally. So that's fixed as well.

Never know what you will run into in this business....

Just a note..a maxumark bracket (get rid of u shaped knc kludge heatsink) and putting on the individual heatsink option on each dc/dc chip

might further reduce his heat....the noctura fan mod at 3000 rpm (20% more noise) vs standard 1500 rpm knc also may help

anyway if you wanted to extend the life of a cube the 10 buck maxumark bracket and heatsinks direct on dc/dc's and maybe the fan is how

I'd go..just a thought to pass on to the guy.

With the above mods my temps on my dc/dc's went down 10-15c on ALL modified dies, this is with the maxumark bracket and the noctura 3000 rpm fan mods.

So my miners in the basement in the summer NOW run at the heat they used to run w/o any mod the previous Winter! 10c-15c is a big deal in real heat output

no more shutting down titans on 90F plus days now....it cut me that much slack in heat etc

brad

that would be me.

I just emailed maxumark for the brackets and heatsinks.  Hopefully he'll accept btc, i'm tapped for the ltc til after this weekend.

I'm in Texas now also.  My cubes were running in Maryland, but i moved to Texas over a year ago.  They've been running nonstop since i've had them (batch 1)

[lightfoot]

Well I'm here at Defcon taking a bit of a break. You can find me pretty easily, I have a mining board instead of a badge around my neck. Feel free to say hi, already have met a few people here.

I'm going to go down to the Hacking village on Friday and see if they would like me to do a talk. I've brought the bag of tricks with me, so I could do a presentation on how to spot and fix some common issues on bitcoin mining gear and how to figure out what's what. If so I'll probably do it Saturday, will check.

Anyone else here and want to hit a bitcoin machine for the hell of it?

C

[LongAndShort]

Well I'm here at Defcon taking a bit of a break. You can find me pretty easily, I have a mining board instead of a badge around my neck. Feel free to say hi, already have met a few people here.

I'm going to go down to the Hacking village on Friday and see if they would like me to do a talk. I've brought the bag of tricks with me, so I could do a presentation on how to spot and fix some common issues on bitcoin mining gear and how to figure out what's what. If so I'll probably do it Saturday, will check.

Anyone else here and want to hit a bitcoin machine for the hell of it?

C

I'm not there, wish i was, have fun mate. Sounds like you are.