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

[lightfoot]

In the meantime here is what a Neptune board looks like ready to have parts pulled:



Note also the Hakko part puller that thing is a literal God for removing stuff. And the Zephlux, the ultimate flux to get stuff off and on boards

[1714189784]

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[1714189784]

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[tlon19]

i have bunch of dead knc gear i could donate.

[lightfoot]

i have bunch of dead knc gear i could donate.

Sure, send it over. What kind of problems have you had over the years?

[Searing]

i have bunch of dead knc gear i could donate.

Sure, send it over. What kind of problems have you had over the years?

what kinda gear may I ask also (lurking)

[lightfoot]

Would going to 8 pin change anything? All it adds are 2 more grounds, still only have 3 12v.

Sorry, I was thinking P2/P2A type connections with 4+12 and 4 grounds. Better but would cause a lot of funny crowbars.

[tlon19]

just pcie connectors melting, overclocking the fuck out of them

[lightfoot]

just pcie connectors melting, overclocking the fuck out of them

That would be a pretty straightforward fix, out of curiosity do you plug them into a powered supply (that snap spark will cause resistance points on the connectors). When they melt the connectors do you just solder the power supply wires straight to the board?

[tlon19]

it starts from the port on the asic side then usually runs the whole cable, i have ram'd atlast 2 vega pus, and two antes 1300 plat.

[tlon19]

lightfoot pm me your address, any chance you can pay for shipping?

[l8nit3]

This is really cool thanks for documenting your progress for us all to check out and use! It's given me the drive to attempt to salvage some old s1's and an s3 (simply to see if i can).

[lightfoot]

No problem, what's the worst that can happen? I do remember when one of the miners I was testing and doing some serious hacking to exploded in a plasma fireball, but that's why you have a fire extinguisher.

[lightfoot]

lightfoot pm me your address, any chance you can pay for shipping?

Will do, absolutely. Do you happen to take some sort of electronic currency, maybe... bitcoin?

[lightfoot]

it starts from the port on the asic side then usually runs the whole cable, i have ram'd atlast 2 vega pus, and two antes 1300 plat.

*nod* Yup, burning cables. The magic thing about it is the hotter the copper gets the higher the resistance and voltage drop. Positive cycle till all hell breaks loose.

For a 600 watt draw that would be 200 watts per wire. At 12 volts that is 16 amps, which should have 12 gauge wire min with 14 gauge really pushing it. 16-18 gauge wire (the kind they use in cheaper supplies) can only handle wait forget it. A 10 foot 18 gauge wire hauling 16a will drop *4* volts. Or 64 watts. Toaster wire.

[lightfoot]

Ok, got the power chip off the board, since the DigiKey order *finally* arrived. Christmas sucks sometimes. :-)

Now, just a quick tip: For these boards pre-heating to 300f then using the air tools at 325 degrees C is not enough to make the chip come loose. Fine. 375 is more than enough. So I don't need to use the "dragon" mode of 450c. That's nice to know.

Need to wait for an hour for cool down, then check all the caps for shorts, then try putting the new chip on and see if the BB brings up all of the power rails. If so we have progress.

[lightfoot]

This is *very* interesting.

So with all chips off I decided to check the pads to ground. Because I noticed one of the caps seemed "shorted" on pin 1 to the tps65217 chip. Still a short. Odd.

Put the new TPS chip on and checked again. Pin 1 shorted to ground. According to the docs, pin 1 is vout2. Odd. So I pulled the filter cap next to pin 1 and ground. Pad still shorted at the chip.

Odd.

Checked the rest of the board. Only other caps on that line are the two under the FPGA pads (FPGA is off). Removed both. OPen circuit to ground. Checked both. One was shorted, put the other back.

Odd.

What I am beginning to think is this: The trimmer caps on the Neptune board can short. When one of them does it drives the associated voltage line to zero and the FPGA is fucked. Checked my other board (the control, did nothing to it) and sure enough, one of the voltage lines is shorted to ground through one of those caps on the left side.

Interesting. Anyone else with a dead-sih neptune board bored this weekend and want to play with a VOM?

[lightfoot]

Powered up the board. Ran the IO powerup

root@Neptune:/etc/init.d# io-pwr init
TPS65217 OK. Modification A, revision 1.1
root@Neptune:/etc/init.d#

In technical parlance: That's it.

Now to see if I can *gently* figure out which cap is blown on the other board here.

Progress!

[lightfoot]

Ok, so anyway I see that my other board has shorted caps somewhere as well, now that I have a board that at least powers stuff I can see where I am:

On the board without the FPGA but with the fixed caps:
Voltages:
3.3 volts is on the left side of the chip along that row of caps.
1.2 volts is on the right side of the chip, between the first four caps (center rail, edge ground)
2.5 volts is on the right side of the chip, outside the last two caps (edge rail, center ground).

These are correct to 3 significant figures, so I think they are highly regulated. My other board has... different values.

I'm going to work on this some more tomorrow, maybe try to put on the FPGA chip after cleaning the pads. Which is always fun.

[lightfoot]

Pulled the bad caps on the other board, and we're up and hashing. So I now know how to fix a blown Neptune board, and probably by extension Triton board and later Jupiter boards.

Mining companies really should hire someone to troubleshoot and fix this stuff. Now on to the next part, fixing the hashing boards...

C

[lightfoot]

Putzing around with board #1 here, this one blew two of the trimmer caps off the board and shorted the third. Right now I need to figure out all of these settings, but it's purring along at 400gh @200 watts, so that's not too bad. All eight supplies are under 60c, which is about as high as I would take them. Really will have to find better ways to cool those DC-DC's, I'm guessing that will take down part of a hashing board.

Will let it purr for a bit, then slow it down for the night.

[Searing]

Pulled the bad caps on the other board, and we're up and hashing. So I now know how to fix a blown Neptune board, and probably by extension Triton board and later Jupiter boards.

Mining companies really should hire someone to troubleshoot and fix this stuff. Now on to the next part, fixing the hashing boards...

C

on the knc swedish miner thread...what is being discussed is if there is ANY differnace on the 6 port boards on either the titan or the neptune (and supposedly by extension at least the jupiter nov boards and just maybe the oct  juptiter/saturn/mercury boards as well.

A guy made a 10 lot run of the bridge adapter daughter boards from the raspberry pi to the 'supposed'  identical 6 port board (neptune etc)

I was told by KNC that the raspberry pi B+ 512mb (I think it was) can be replaced w/o issue if the PI is broke (or at least what knc tech said on forums back in the day
when broken pi's showed up...damn wish someone would have archived forums ..i to go way back machine and it ends at the titles damn it so close)

Also this Titan Bridge should work for folk with blown Titan Bridges

the last 'hurrah' is to take a bought PI and this clone board and fire it up on a Neptune board (and go down to the other boards as bravery strikes) and see if WITH  the
clone bridge ACTUALLY have a work around for Titan Controllers...

Alas no one is brave enough to toss out a cube...I'm hoping someone someplace has a Titan cube that is so IFFY or so LAME in hashing like 1 die working at low settings and/or
a cube that works in some manner but flakes out after 2 hrs or something...I mean real ugly no use for the Titan cube ...except for perhaps it could run for say 15min in some manner
badly or not to prove the concept that the above arrangement would work

Likely the FPGA is firmware on the 6 port card is different on the chip between Titan and Neptune 6 port card ..but knc are 'evil' don't ya know ..would be like them to just ahem 'recycle' old Jupiter 6 port boards from their farm as they pulled them to put in Neptunes and recyled them into use on the Titans (if so another well played evil genius fix by knc)

anyway thought it was of note here with your fixes and delving into the Neptune board if/any differances or whatever you can point out

but where such meanderings are on the swedish asic thread below

https://bitcointalk.org/index.php?topic=170332.0

Myself at a 'guess' I'd put the odds at about 70/30 that the only diff between the Titan Controllers and the Neptune Controllers is the PI and the bridge and the SD firmware

anyway like the work you are doing on this thread ..interesting thou I don't have a Neptune. (Do have a Jupiter ..would be nice to convert this up to titan controller someday dare to dream)