ISAWHIM
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May 16, 2014, 02:38:37 AM |
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Bzzzt. Other way around. Caps in parallel add together. 1+1=2 ect. In series they divide. Resistors of course do oposite. series adds, parallel is 1/((1/r1)+(1/r2)+ etc.) Arg... I hate when I do it backwards... No wonder I can't ever get my woman pregnant! xD Well, in that case, since I was backwards... the capacitance is half what it should be. Can't believe I reversed parallel and series. I know that a screw has a resistance of near zero... lol, which was across both pads, where the resistor should have been. Thus, nullifying the existence of the cap, as that was a direct short to the + terminal side, from the - ground.
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FrictionlessCoin
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May 16, 2014, 02:43:54 AM |
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Bzzzt. Other way around. Caps in parallel add together. 1+1=2 ect. In series they divide. Resistors of course do oposite. series adds, parallel is 1/((1/r1)+(1/r2)+ etc.) Arg... I hate when I do it backwards... No wonder I can't ever get my woman pregnant! xD Well, in that case, since I was backwards... the capacitance is half what it should be. Can't believe I reversed parallel and series. I know that a screw has a resistance of near zero... lol, which was across both pads, where the resistor should have been. Thus, nullifying the existence of the cap, as that was a direct short to the + terminal side, from the - ground. The capacitors are just there to modulate the voltage, it is not really critical that you have a little less than normal. I think the main problem has been the heatsinks. The top heatsinks are too small, the bottom heatsinks have not enough thermal conductivity due to lack of paste.
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NotFuzzyWarm
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May 16, 2014, 02:45:44 AM |
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Would be nice to have a schematic of the circuits. The myrid of smaller caps are either across data lines for shaping the data eye or more likely there to knock out very high freq ripple. Is not just the total value of capacitance use but how it is achieved.
A capacitors internal reactance changes with frequency (think crossovers). Large value caps great at lower freq but roll off as it climbs. So is very common to also use several smaller caps to handle the higher freqs. What is the clock freq in the A1? They need to filter 2x that frequency so the switching transitions can be dampened out.
Also is why high freq switching regulators use all them little caps vs a couple big ones.
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NotFuzzyWarm
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May 16, 2014, 02:54:12 AM Last edit: May 16, 2014, 03:07:12 AM by NotFuzzyWarm |
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If you have a scope it would be interesting to see what the 'filtered' Vdd feeding each side looks like. Betcha the voltages are different. Ones w/o caps will probably have bigger dips & spike at 2x the clock freq.
And def right on the heatsinks. That is prob #1. My thing on the power comes from the industrial 24x7x365 running mindset. It is sooo easy to do it right the 1st time and be done with it rather than fart around with 'adequate'. Bites ya in the ass every time.
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NotFuzzyWarm
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May 16, 2014, 03:11:15 AM Last edit: May 16, 2014, 03:44:52 AM by NotFuzzyWarm |
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I wonder how the power internal to the chips is bussed. One can assume that all Vdd pads are tied together at various points, question is, how much do they rely on the main feeds from the pads to be in balance to keep from burning out spots in the internal traces? I would think they can tolerate a local 2x overload at best. eidt: looking at that that kemet info is great - very good coverage on exactly we are talking about on bypassing
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ISAWHIM
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May 16, 2014, 12:27:14 PM |
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I wonder how the power internal to the chips is bussed. One can assume that all Vdd pads are tied together at various points, question is, how much do they rely on the main feeds from the pads to be in balance to keep from burning out spots in the internal traces? I would think they can tolerate a local 2x overload at best. eidt: looking at that that kemet info is great - very good coverage on exactly we are talking about on bypassing Gave me an idea... lol... throwing the non-responding card back in...
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opieum2
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May 16, 2014, 02:37:03 PM |
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So the issues with the board are indeed hardware then? Software won't fix it?
I will be finally plugging in the system and powering up tonight. I was stuck at a client site most of the day yesterday so I had no chance to work on it. The OS is pretty much ready (minus web interface I will bring the AMT interface over after this portion works)
Knock on wood and hope this works. I got all the software ready. Was not hard to set up the distro itself, most of the work was in making sure the right hardware support was compiled into cgminer. I am hoping there are not different driver registers that cause the cards not to read (which I think is why the bitmine firmware did not work for me). If so I will have to find the registers and add them in manually into the driver code and rebuild. This would be the only issue I anticipate right now.
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"amtminers scam joshua zipkin scammer" -Joshua Zipkin leaked skype chats http://bit.ly/1s7U2Yb-For bitcoin to succeed the community must police itself.
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timmyd
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May 16, 2014, 04:41:31 PM |
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Its beyond a joke pal i really wish i had never come across amt, worst decision of my life honestly im normally good at watching out for dodgy deals and scammers but this time i got caught out, Thanks for the link pal good look with your claim
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ladi4ever
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May 16, 2014, 05:15:49 PM |
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Its beyond a joke pal i really wish i had never come across amt, worst decision of my life honestly im normally good at watching out for dodgy deals and scammers but this time i got caught out, Thanks for the link pal good look with your claim You're not the only one bro, they screwed many people like you and me..
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NotFuzzyWarm
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May 16, 2014, 05:37:48 PM |
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Hi guys im back been a while since my last post here, you may remember that i did finally recieve a 520ghs miner from amt order number #1450, you may also remember the poor condition it arrived in and the fact that it didnt even mine, 1 chip even burnt out on 1 card, well since then <snip>
Man that 1st sentence was a long one... Anywho, at least you got *something* even if it is a paperweight. I also ordered a 520, In my case I only went with that from AMT because the 520 was not advertised as pre-order. It was falsely advertised as 'delivery in 4 weeks or less' implying they were in production... I even asked for a DIY when they made the offer. Too bad they didn't follow through as I along with opieum2, ISAWHIM maybe a few others here are ideal folks to get the kits so we can figure out what is wrong with them and come up with fixes. Or - certify design & manufacturing issues caused by their contract manufacturer. Oh well, AMT's loss. And mine
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opieum2
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May 16, 2014, 05:42:27 PM |
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Its beyond a joke pal i really wish i had never come across amt, worst decision of my life honestly im normally good at watching out for dodgy deals and scammers but this time i got caught out, Thanks for the link pal good look with your claim We are all automatically included in it. The big question is whether we will come out of it or not "whole" If AMT doesn't have much we are stuck with the short end of it. It likely will be the case IMO no matter how its sliced. I guess it depends on what there is available for us. I didn't put in any claim. I think they got plenty from everything being said here. And at this point or even before it was irrelevant.
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"amtminers scam joshua zipkin scammer" -Joshua Zipkin leaked skype chats http://bit.ly/1s7U2Yb-For bitcoin to succeed the community must police itself.
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opieum2
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May 16, 2014, 06:19:38 PM |
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Looks like a couple of my comments got deleted. I was pretty pissed that day over the lack of replies and had a moment. Oh well. I get inconsistent responses anyway after trying to work with them. As an FYI AMT put an offer out to get me two new miners two replace the two fried ones I have. I have not seen or heard anything since that offer. I accepted it even. I don't have any word on status of this. But I have given up trying to communicate as I, like everyone else is getting nowhere.
Since they are deleting days old posts they might want to be aware that the mirror hosts these posts as well and those cannot be removed. Plus I have a record of the removed posts in my PM box so I can always repost them. I likely wont though as its not worth it and I was pissed off when I wrote those (not that it makes it any less wrong what I wrote). Anyway in spite of that I am still working to solve what could be a software problem with these miners not just for me but for others. It might benefit AMT (if they are still in business after the lawsuit) as well the work we are all doing here, but ultimately we are doing it for the people who got screwed with faulty hardware. Those of us all working to get the miners working at least are working together to help each other out. We are not likely to see any compensation from AMT for that effort anyway.
I still maintain they were legit but screwed up royally, but just had alot of bad situations and fucked up royally on the communication. But I figure its just shitty planning that got them here and allot of false assumptions and not keeping on top of regulations and things like that. I don't totally think they were looking to screw people over but the shitty planning that led them to this mess just got worse and worse and was unmanageable. I said from the start if they were able to just properly communicate and set proper expectations none of this would even be an issue. Sure the lawsuit would have happened likely anyway as they were dragging things out. But the first problem was lying (or misleading us) about expectations and dates. The truth would have been just fine. Hey guys we have problems with IMET, we also have problems with bitmine we are sorting out....compensation coming....that would have helped to some extent. But if the goal was to not give compensation this is why they are where they are at now.
Anyway thought I would comment on my deleted posts.
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"amtminers scam joshua zipkin scammer" -Joshua Zipkin leaked skype chats http://bit.ly/1s7U2Yb-For bitcoin to succeed the community must police itself.
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FrictionlessCoin
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May 16, 2014, 06:23:44 PM |
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Looks like a couple of my comments got deleted. I was pretty pissed that day over the lack of replies and had a moment. Oh well. I get inconsistent responses anyway after trying to work with them. As an FYI AMT put an offer out to get me two new miners two replace the two fried ones I have. I have not seen or heard anything since that offer. I accepted it even. I don't have any word on status of this. But I have given up trying to communicate as I, like everyone else is getting nowhere.
Since they are deleting days old posts they might want to be aware that the mirror hosts these posts as well and those cannot be removed. Plus I have a record of the removed posts in my PM box so I can always repost them. I likely wont though as its not worth it and I was pissed off when I wrote those (not that it makes it any less wrong what I wrote). Anyway in spite of that I am still working to solve what could be a software problem with these miners not just for me but for others. It might benefit AMT (if they are still in business after the lawsuit) as well the work we are all doing here, but ultimately we are doing it for the people who got screwed with faulty hardware. Those of us all working to get the miners working at least are working together to help each other out. We are not likely to see any compensation from AMT for that effort anyway.
I still maintain they were legit but screwed up royally, but just had alot of bad situations and fucked up royally on the communication. But I figure its just shitty planning that got them here and allot of false assumptions and not keeping on top of regulations and things like that. I don't totally think they were looking to screw people over but the shitty planning that led them to this mess just got worse and worse and was unmanageable. I said from the start if they were able to just properly communicate and set proper expectations none of this would even be an issue. Sure the lawsuit would have happened likely anyway as they were dragging things out. But the first problem was lying (or misleading us) about expectations and dates. The truth would have been just fine. Hey guys we have problems with IMET, we also have problems with bitmine we are sorting out....compensation coming....that would have helped to some extent. But if the goal was to not give compensation this is why they are where they are at now.
Anyway thought I would comment on my deleted posts.
Crazy, the only communication we get from AMT are 'deleted posts'. I don't even know why they even bother to delete posts. C'mon, it is not like they have any reputation left to uphold.
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opieum2
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May 16, 2014, 06:26:25 PM |
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Getting back to technical.....so is the issue with the cards blowing a hardware problem then? The traces shorting or some other component causing problems? I would presume a single chip blowing would still allow the rest of the card to function unless there was some kind of daisy chain that cuts the electrical flow.
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"amtminers scam joshua zipkin scammer" -Joshua Zipkin leaked skype chats http://bit.ly/1s7U2Yb-For bitcoin to succeed the community must police itself.
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FrictionlessCoin
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May 16, 2014, 06:33:05 PM |
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Getting back to technical.....so is the issue with the cards blowing a hardware problem then? The traces shorting or some other component causing problems? I would presume a single chip blowing would still allow the rest of the card to function unless there was some kind of daisy chain that cuts the electrical flow.
Oh.... I had thought the chips were daisy chained. You mean they are not? You mean we can individually remove chips from the board and it will still work? Is that correct?
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opieum2
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May 16, 2014, 06:40:56 PM |
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<snip>
Crazy, the only communication we get from AMT are 'deleted posts'. I don't even know why they even bother to delete posts. C'mon, it is not like they have any reputation left to uphold. Not even stressing it now. writing it was enough. If they want to communicate (or send the replacement hardware) they know how to. I am more than willing to bury the hatchet for my part if they were to just keep me in the loop on replacing the hardware with tested working units. That for me at this point would be enough to move on from this now. My frustration is mostly centered around the fact that I get a communication with options and I reply and then nothing. I imagine the lawsuit has them up their ears in crap, but they did state they were running business as usual. I know both legal parties are viewing all this anyway. My loyalty is to the truth of the matter. I will say this....I still don't think they are/were a scam. A scam is really just a grab and run operation. They do have/had a product, regardless of quality and execution. Their handling of the business side of things as well as their over-promise under-deliver as well as lack of effective communication is what led to this whole mess for them. Bitmine is dealing with similar things as well (to a lesser extent). All said and done not a scam IMO....just poorly run is all. This would be a shitty scam if they didn't have an easy exit strategy to get people's money. And they don't. They actually are still around. Hopefully out of all this we get working miners with proper QA done on them or compensated for our losses.
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"amtminers scam joshua zipkin scammer" -Joshua Zipkin leaked skype chats http://bit.ly/1s7U2Yb-For bitcoin to succeed the community must police itself.
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opieum2
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May 16, 2014, 06:43:03 PM |
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Getting back to technical.....so is the issue with the cards blowing a hardware problem then? The traces shorting or some other component causing problems? I would presume a single chip blowing would still allow the rest of the card to function unless there was some kind of daisy chain that cuts the electrical flow.
Oh.... I had thought the chips were daisy chained. You mean they are not? You mean we can individually remove chips from the board and it will still work? Is that correct? That is what I don't know. I know the cards are daisy chained on the backplane. But the chips on the card is what I am not sure of. Without any further info or documentation on the design we have no idea. I will need to take a closer look as I actually haven't. I probably will later after I get some time to sit down for a while and work on it.
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"amtminers scam joshua zipkin scammer" -Joshua Zipkin leaked skype chats http://bit.ly/1s7U2Yb-For bitcoin to succeed the community must police itself.
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NotFuzzyWarm
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May 16, 2014, 06:46:44 PM Last edit: May 16, 2014, 07:08:27 PM by NotFuzzyWarm |
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Getting back to technical.....so is the issue with the cards blowing a hardware problem then? The traces shorting or some other component causing problems? I would presume a single chip blowing would still allow the rest of the card to function unless there was some kind of daisy chain that cuts the electrical flow.
We will have to hear back on whatever isawhim's idea is with the not-responding board. It does seem that some of the local decoupling caps are missing/erroneously changed with resistors. The traces we were talking about are 2 different things, one being the boards power-planes being shorted by a screw. In that case - or a chip shorting - then the single Vcore regulator they use for each board is going to try and feed all the power it can into the short until it is burned open. If the short is to sturdy to burn open it is going to kill the whole card and possibly also cause the PSU to shut down. My ruminations are about the A1 chips internal power routing: There are 7 power pads feeding in Vdd: 4 very large ones, 2 smaller ones in 2 corners plus one more very small one. If for whatever reason all the big Vdd pads are not connected from bad soldering or not properly bypassed (missing caps) then it is very possible that connections inside the chip which are still getting power could overload and open up killing the chip. Methinks isawhim is going to try and get around that.
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NotFuzzyWarm
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May 16, 2014, 06:53:45 PM |
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Getting back to technical.....so is the issue with the cards blowing a hardware problem then? The traces shorting or some other component causing problems? I would presume a single chip blowing would still allow the rest of the card to function unless there was some kind of daisy chain that cuts the electrical flow.
Oh.... I had thought the chips were daisy chained. You mean they are not? You mean we can individually remove chips from the board and it will still work? Is that correct? That is what I don't know. I know the cards are daisy chained on the backplane. But the chips on the card is what I am not sure of. Without any further info or documentation on the design we have no idea. I will need to take a closer look as I actually haven't. I probably will later after I get some time to sit down for a while and work on it. In the 2-chip reference design on github the chips themselves are daisy-chained for the SPI coms. Goes in one side and comes out the other. If you pull a chip I'd guess that you just need to place 2 jumpers on the boards pads to pass the data on to the next in line. Again, don't have any hardware here much less the new boards layout/schematic to verify that.
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