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Topic: New Official AMT Thread - page 23. (Read 149472 times)

newbie
Activity: 52
Merit: 0
August 11, 2014, 02:56:16 PM
sr. member
Activity: 267
Merit: 250
Stan the Man!
August 11, 2014, 01:59:38 PM
hero member
Activity: 532
Merit: 500
August 11, 2014, 01:07:45 PM
It's not hard to believe that AMT had a botched design from the get-go. Probably due to ZERO testing before sending to production.

Now they want to blame IMET and say refunds are held up due to them.

Ha, way to pass the buck AMT.

You guys are fucking pathetic. At this point if no one is refunded, criminal charges should be pressed.

Has a SINGLE person received a miner yet?

EXACTLY a single person. And he only got half his order apparently. Go back to page 125 I believe it starts around there. "The rest have shippedTM."
newbie
Activity: 52
Merit: 0
August 11, 2014, 08:29:18 AM
Application of thermal paste and mechanical assembly including mounting boards to heatsinks was not Imet's responsibility.  All soldering meets IPC class 2 and inspection was done by trained personal.  Everything was in order when delivered to AMT.  The likely cause of your boards not working is overheat.  The heatsinks used on the top of the ASICS are not adequate to dissipate the required 30 percent.
Yes the top sinks were woefully under sized. However, bet the rig you posted as running fine has the same tiny sinks, no?
Just that the final flaming nails in the coffin are the missing thermal bumps on back side of the board that are supposed to complete the thermal contact path to the main heat sink. I refer you to my previous post on this https://bitcointalksearch.org/topic/m.7610781

I have sample boards ranging from no thermal bumps at all to most all there. On average I see what is shown in the above post - most missing meaning that there is no way in hell to make decent contact with the main heat sink as the few bumps present act as jacks raising the board up from the sink. Thermal compound no matter how carefully applied (or drunkenly slathered on) will not compensate for the 8mil gap. So much for the 70% of heat flow path.

AMT was not responsible for those bumps. The CM was. If they were not explicitly called out in the BOM from AMT/Bitmine (my copy makes no mention of them nor having filled thermal vias) then either have none or all of them. Period. If you have ever worked with power devices before you *have* to had known that. Given that some/many bumps are there tells me you knew about the thermal loads the A1 has. After that  Roll Eyes

Then there is the dpot chip substitution without regard to the core voltage divider reference circuit it controls... Ohm's Law applied to parallel resistances anyone? Frankly, aside from the legal who-did or didn't do-what points, this is all just stomping around in the rotting carcase of a long beaten to death horse.
No, the rig that I posted did not have the tiny sinks.  I built my own prototype and measured the ASICS with a thermocouple.  I then redid the thermals and mechanicals.  The bumps that you describe are not intentional.  They are created when solder flows through the thermal vias and cannot be controlled.  There are ways to get good thermal contact with and without the bumps.  Lastly, I know nothing about a dpot substitution.  We installed what was on the parts list supplied.     
legendary
Activity: 3822
Merit: 2703
Evil beware: We have waffles!
August 11, 2014, 02:00:58 AM
Application of thermal paste and mechanical assembly including mounting boards to heatsinks was not Imet's responsibility.  All soldering meets IPC class 2 and inspection was done by trained personal.  Everything was in order when delivered to AMT.  The likely cause of your boards not working is overheat.  The heatsinks used on the top of the ASICS are not adequate to dissipate the required 30 percent.
Yes the top sinks were woefully under sized. However, bet the rig you posted as running fine has the same tiny sinks, no?
Just that the final flaming nails in the coffin are the missing thermal bumps on back side of the board that are supposed to complete the thermal contact path to the main heat sink. I refer you to my previous post on this https://bitcointalksearch.org/topic/m.7610781

I have sample boards ranging from no thermal bumps at all to most all there. On average I see what is shown in the above post - most missing meaning that there is no way in hell to make decent contact with the main heat sink as the few bumps present act as jacks raising the board up from the sink. Thermal compound no matter how carefully applied (or drunkenly slathered on) will not compensate for the 8mil gap. So much for the 70% of heat flow path.

AMT was not responsible for those bumps. The CM was. If they were not explicitly called out in the BOM from AMT/Bitmine (my copy makes no mention of them nor having filled thermal vias) then either have none or all of them. Period. If you have ever worked with power devices before you *have* to had known that. Given that some/many bumps are there tells me you knew about the thermal loads the A1 has. After that  Roll Eyes

Then there is the dpot chip substitution without regard to the core voltage divider reference circuit it controls... Ohm's Law applied to parallel resistances anyone? Frankly, aside from the legal who-did or didn't do-what points, this is all just stomping around in the rotting carcase of a long beaten to death horse.
newbie
Activity: 52
Merit: 0
August 10, 2014, 10:55:51 PM
legendary
Activity: 1764
Merit: 1756
Verified Bernie Bro - Feel The Bern!
August 10, 2014, 10:48:04 PM
newbie
Activity: 52
Merit: 0
August 10, 2014, 10:43:22 PM
The likely cause of your boards not working is overheat.  The heatsinks used on the top of the ASICS are not adequate to dissipate the required 30 percent.
Electronics solder melts around 185 C (365 F), correct?

No, 217C for lead free.  Leaded is lower as suggested but the AMT boards are lead free.  This is during the assembly process.  The ASICS need to be kept well below the 100C rating for them to be happy when power is applied and they are running.  The ASICS burn up almost immediately when not heatsinked properly.  Once one goes, the whole board is down because the A1s are daisychained.
hero member
Activity: 910
Merit: 1003
August 10, 2014, 10:39:35 PM
The likely cause of your boards not working is overheat.  The heatsinks used on the top of the ASICS are not adequate to dissipate the required 30 percent.
Electronics solder melts around 185 C (365 F), correct?
newbie
Activity: 52
Merit: 0
August 10, 2014, 10:30:21 PM
newbie
Activity: 26
Merit: 0
August 10, 2014, 05:12:49 AM
I sent my pool information as instructed and have seen no hashing activity. I, of course am also waiting on my 1.2TH model I ordered in early December of last year. Just a reminder more or less. Everyone makes mistakes, and I appreciate the efforts to make good on them. Thanks.
hero member
Activity: 854
Merit: 500
Just a regular guy who likes his fiber.
August 10, 2014, 12:19:13 AM
I'll make my weekly monday call to DHL and see if there is anything on the way. That will be the 11th and with a two day shipping should be here on the 13th. I'm some hoe now assuming that it will arrive by then. I hope that isn't the case though. 
legendary
Activity: 3822
Merit: 2703
Evil beware: We have waffles!
August 09, 2014, 09:14:31 PM
Mine is still down.
As is mine again... Roll Eyes
Must be Clenells' Fault™ heh heh.
hero member
Activity: 532
Merit: 500
August 09, 2014, 08:35:51 PM
vip
Activity: 1428
Merit: 1145
August 09, 2014, 08:26:31 PM
Didn't they ship ALL MINERS two weeks ago?

Everyone will have their miners in 5-7 daysTM.



It's probably Clenells fault...

It's clenells faultTM.

It's Clenells' Fault™
hero member
Activity: 532
Merit: 500
August 09, 2014, 08:16:48 PM
Didn't they ship ALL MINERS two weeks ago?

Everyone will have their miners in 5-7 daysTM.



It's probably Clenells fault...

It's clenells faultTM.
legendary
Activity: 1764
Merit: 1756
Verified Bernie Bro - Feel The Bern!
August 09, 2014, 08:16:02 PM
Didn't they ship ALL MINERS two weeks ago?

Everyone will have their miners in 5-7 daysTM.



It's probably Clenells fault...
hero member
Activity: 532
Merit: 500
August 09, 2014, 08:10:40 PM
Didn't they ship ALL MINERS two weeks ago?

Everyone will have their miners in 5-7 daysTM.

sr. member
Activity: 378
Merit: 250
August 09, 2014, 08:01:45 PM
Didn't they ship ALL MINERS two weeks ago?
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