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Topic: New Official AMT Thread - page 87. (Read 149453 times)

hero member
Activity: 504
Merit: 500
May 19, 2014, 09:45:46 PM
Mmm. Guess we gave them somethings to chew on for a while Cheesy

I requested some driver info so I can get these things working. That is my hold up at the moment. I might be able to get it working without the driver info, I am still working at it.

Why do you need a new driver when a couple of folks supposedly don't have a problem running the system?
Because some of us do...

That is like windows saying, why patch windows, it works for a few... xD

Though, for my situation, where I am seeing the miner increase in hashing over time, on the faulting cards... It will not make much difference. It was the faulting cards stopping the rest of the cards from operating normally. However, something is still causing the boot-up failure to stop at "MONITOR".

In all honesty, I want the new software, just so I can tune the hashing-power, where I can not now. Especially when the errors get so high, that the hashing-power indicated on the screen, is not reflected in the hashing-results in the pool, due to the errors being obviously not sent, or rejected by the server after being sent. However, that is not my primary concern at the moment. My concern is getting more than 2 cards running.

Also, getting hold of at-least one more heat-sink, so I can run my system as 3 and 3 cards. At the moment, I only have five heat-sinks. Three are on cards that no longer function. (Well, they no longer show in the system, when hooked-up.) The power-supply I have coming, has no use until I can get at-least three more cards running. So I at-least have five hashing.
hero member
Activity: 504
Merit: 500
May 19, 2014, 09:45:04 PM
Mmm. Guess we gave them somethings to chew on for a while Cheesy

Yes I noticed the large negative ground-shielding, surrounded by large positive plates, which is the essence of an electrical capacitor. (Two plates of opposite polarity, separated by a layer of non-conductive medium.) Might explain the electrical run-off that is causing the VR to bump-up in time, which leads to ever-increasing voltage, leading to more capacitance, leading to more increasing voltage.

I am just not sure why one board does this, over another board, being all of the same design. With exception to the issue of substituted parts that may be leading to the failure. So hard to see some of the numbers of the smaller components.

I will be mapping-out the contacts tonight, and grinding-down one heat-sink, a fraction of a MM, which should be enough to avoid any thermal-grease issues, avoid all potential through-hole contacts, and give a more localized point of pressure contact. With less metal resting against the PCB itself.

I will be grinding the contact points about 1 MM smaller than the exposed metal, since the excess compound will squish-out to that small gap.

Going to look at the caps, and check the values.

P.S. I got my invoice today... Though it indicates the incorrect price. I paid $6089.00 not $5599.00 as the invoice indicates. (That was the earlier price, which I had just missed. I had to pay the $6089.00 price. Which is indicated on the AMT website invoice.)
legendary
Activity: 868
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May 19, 2014, 09:39:23 PM
Mmm. Guess we gave them somethings to chew on for a while Cheesy

I requested some driver info so I can get these things working. That is my hold up at the moment. I might be able to get it working without the driver info, I am still working at it.

Why do you need a new driver when a couple of folks supposedly don't have a problem running the system?
hero member
Activity: 532
Merit: 500
May 19, 2014, 09:34:32 PM
Mmm. Guess we gave them somethings to chew on for a while Cheesy

I requested some driver info so I can get these things working. That is my hold up at the moment. I might be able to get it working without the driver info, I am still working at it.
legendary
Activity: 3752
Merit: 2667
Evil beware: We have waffles!
May 19, 2014, 09:17:19 PM
Mmm. Guess we gave them somethings to chew on for a while Cheesy
hero member
Activity: 588
Merit: 500
May 19, 2014, 08:39:18 PM
Been staying quiet on here up to press due to not wanting to be a fan boy or amt shill as i have been called.

*update*
Mine and mellorbos rig has had 100% uptime since arrival minus user issues being putty shutdowns ethernet cables dropping out and general wtf moments.
 tried a variety of alt coins some work better than others but evidently give the same 0.03 btc a day.

share sizes have now dropped from the original 80000 sats btc th approx 59000 sats btc. no special anything just lots and lots of fans and the gigantic antec case fan on top.

on a side not the rig is keeping the room it is in at a steady 34*c in the late uk evening a little more through peak sun.

i to recieved an invoice for the order recieved hopes im receiving another one :-)

glad to see your still in here amt despite having 90% of your tongue cut out.
sr. member
Activity: 392
Merit: 250
May 19, 2014, 08:20:49 PM
Yes very close.   Is thermal paste conductive?
For the vast majority on the market, not at the voltages used on these. Possibly a bit capcitive but that is more an issue if it is smeared across bare connections.
Possibly corrosive to aluminum though if containing silver.

That would take a while to get the point of corrosion, some of the pastes did contain silver, like the Arctic Silver 5 thermal paste. In general,  despite it having silver we have not found that as the main reason for the problems. The main problem lies in the amount of copper in the board itself, which we had not discovered until recently.
Amount of copper? As in the cladding being to thin for the currents/thermal loads involved perhaps?

perhaps.
sr. member
Activity: 392
Merit: 250
May 19, 2014, 08:20:28 PM

http://www.aavid.com/

Pricy, but fast.
You should have two types of boards.

1st with the 4 caps surrounding the chips.
2nd with the only 1 cap out of the 4 in that location.

- First board- this was the original design, provided by bitmine, which also called for a 12x 1500 cap where you'll see the 12x 560 cap there. The manufacturer ordered this component switch which differed from the bom.

- beneath the 560 caps you'll see another location 170 cap on the first board and 330 on the 2nd version with (1500 caps).

The ability to put a railed heatsink exists on the second version but could not exist on the first.
you - and anyone else working on this - list your question in a simple form which allows for an easy to follow response.


ie.  Which value should this component be - snap a pic or something. End post.

So what are you saying?  We can remove any number of caps leaving at least one and it should work the same.  That way we can add a adequate heat sink.  Not the time piece that it currently has.   



No, you can't do anything and we don't advise that you try anything either.  If your board has 4 caps, you have a 560 cap on the psu.  If you  have 1 cap, you have 1500 caps on the psu.  The difference is 20,000mmf.
legendary
Activity: 3752
Merit: 2667
Evil beware: We have waffles!
May 19, 2014, 08:17:08 PM
Yes very close.   Is thermal paste conductive?
For the vast majority on the market, not at the voltages used on these. Possibly a bit capcitive but that is more an issue if it is smeared across bare connections.
Possibly corrosive to aluminum though if containing silver.

That would take a while to get the point of corrosion, some of the pastes did contain silver, like the Arctic Silver 5 thermal paste. In general,  despite it having silver we have not found that as the main reason for the problems. The main problem lies in the amount of copper in the board itself, which we had not discovered until recently.
Amount of copper? As in the cladding being to thin for the currents/thermal loads involved perhaps?
sr. member
Activity: 392
Merit: 250
May 19, 2014, 08:14:49 PM
Yes very close.   Is thermal paste conductive?
For the vast majority on the market, not at the voltages used on these. Possibly a bit capcitive but that is more an issue if it is smeared across bare connections.
Possibly corrosive to aluminum though if containing silver.

That would take a while to get the point of corrosion, some of the pastes did contain silver, like the Arctic Silver 5 thermal paste. In general,  despite it having silver we have not found that as the main reason for the problems. The main problem lies in the amount of copper in the board itself, which we had not discovered until recently.
legendary
Activity: 3752
Merit: 2667
Evil beware: We have waffles!
May 19, 2014, 08:13:29 PM
AMT_Miners: If you want a board physical design review pm me. I've been involved in power systems not to mention a helluva lot of other circuit design for almost 40 years...
hero member
Activity: 532
Merit: 500
May 19, 2014, 08:10:04 PM
@AMT I sent you guys an email regarding some info regarding the drivers, that is a critical point in making this new firmware work. I have already added some datacenter friendly tools to make this large scale monitor friendly. Ideally I would port your webUI over if you have documentation on that, otherwise I will just try to get phpminer working. A more experienced dev than I already volunteered to assist me with that front.
sr. member
Activity: 392
Merit: 250
May 19, 2014, 08:04:42 PM

Yea, those seem to be the largest source of heat, once the cards stop functioning. May be the coils insulation failing. Those too, it seems, are not real flush-mounted to the board. There are exposed heat-pads under them, on the heat-sink side. However, the varnish actually raises the heat-sink from direct contact to the metal at all. (Looks like the heat-sinks should be machined to match the pads, but they are not. They are essentially using the heat-sink compound to "fill the gap" between the exposed heat-pad and the heat-sink, which is not the function of thermal grease. Thermal grease is designed to fill the microscopic gaps, not gaps of zero-contact. Which is where heat-pads are designed to function.)

Did notice another thing that bugs me a little, about the cards... The PCB sticks-out beyond the heat-sinks, by a fraction of a MM... This bugs me because the frame mounts firmly to the cards by the heat-sink, which has a metal-edge pressing hard against the PCB itself. This too stresses the PCB, and I am not 100% sure that the inner layers may or may not have any stray "copper traces" near the edges, which are in direct contact with the metal frame. Mostly, my concern is the compression of the PCB, as the aluminum expands and contracts from the heat. (This also being a concern due to the solid screw mounting which is firmly holding the non-expanding fiberglass PCB to the expanding alu
Ja the buck inductors are supposed to be in contact with *something* to suck out some of the waste heat. Along those lines, got a part number on them? With all that is turning up would be a good idea to make sure they are running under their max dc-current rating. If over it then the cores will saturate and say goodbye to regulation.

On traces near the edges:  If whoever laid out the boards knows anything about EMC basics then all traces will be at least 2x the board thickness away from the edges to close near-field loops. Any closer and emissions goes through the roof from the loops becoming true radiated EMI.

Um, that rather raises a point - have these been EMC tested at all? Not sure if miners fall under FCC much less EU exempted equipment...

Yes you are correct regarding the potential shorts. Traces are close to the edges yes.
legendary
Activity: 3752
Merit: 2667
Evil beware: We have waffles!
May 19, 2014, 08:04:04 PM
Yes very close.   Is thermal paste conductive?
For the vast majority on the market, not at the voltages used on these. Possibly a bit capacitive but that is more an issue if it is smeared across bare connections.
Possibly corrosive to aluminum though if containing silver.
sr. member
Activity: 392
Merit: 250
May 19, 2014, 08:00:45 PM


Here is the back side.... doesn't appear to have any layer improperly exposed.

First 300 boards. If there are no exposed via's on your board then I guess you're board isn't one of the first 300 and was tested and worker when shipped.
legendary
Activity: 868
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May 19, 2014, 07:55:39 PM


Here is the back side.... doesn't appear to have any layer improperly exposed.
At least that bit of boards looks covered. Remember they dis say that many - not all boards had the uncovered via fault.

Center left is a major no-no that thu-hole for screws is way way too close to those covered vias either side of it. Pressure IS going to cause faults in the screen layer.

Yes very close.   Is thermal paste conductive?
legendary
Activity: 3752
Merit: 2667
Evil beware: We have waffles!
May 19, 2014, 07:50:24 PM


Here is the back side.... doesn't appear to have any layer improperly exposed.
At least that bit of boards looks covered. Remember they dis say that many - not all boards had the uncovered via fault.

Center left is a major no-no that thu-hole for screws is way way too close to those covered vias either side of it. Pressure IS going to cause faults in the screen layer.
legendary
Activity: 3752
Merit: 2667
Evil beware: We have waffles!
May 19, 2014, 07:42:39 PM
Well if they were indeed shorting...  that problem would have been identified with initial testing.

Don't tell me that these systems where shipped without testing??!

If the layer where improperly exposed, then one could have easily made temporary fix by taping the exposed parts.
Depends. Initially the thermal pad may have kept may/most from shorting out so any initial test would have passed. Unless there were pointy bits that is. After that things moving from thermal cycling and just time will be enough for it pierce the pads. It may well explain the delayed-death syndrome we have been seeing...

Yes Mylar tape would fix that. And again care must be taken to allow for that added gap produced. So far I would not count on that as it strikes me that whoever designed/reviewed the design of all this have zero-experience at it.
legendary
Activity: 868
Merit: 1000
Cryptotalk.org - Get paid for every post!
May 19, 2014, 07:39:23 PM


Here is the back side.... doesn't appear to have any layer improperly exposed.
legendary
Activity: 868
Merit: 1000
Cryptotalk.org - Get paid for every post!
May 19, 2014, 07:32:00 PM
[quote author=FrictionlessCoin link=topic=569769.msg6823734#msg6823734
What are you saying here?   The manufacturer had exposed vias that assumes the use of a thermal transfer pad.... was a thermal transfer pad used?   
No I take it as the signal and power vias were left uncovered leading to them shorting. Only the thermal xfr vias should be bare. And - due to the thickness of the green/red screen layer that is supposed to seal the boards one damn well better make sure that something bridges the resulting gap between the sinks and the thermal vias.
[/quote]

Well if they were indeed shorting...  that problem would have been identified with initial testing.

Don't tell me that these systems where shipped without testing??!

If the layer where improperly exposed, then one could have easily made temporary fix by taping the exposed parts.
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