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Author Topic: Cheap and simple repair of S7 hash board  (Read 27693 times)
ruinous
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February 05, 2018, 07:01:20 PM
 #161

Thanks I got a read, I was using AC not DC settings Sad

Card in question is 10.7v with 30 asics displaying "-" 's and goes to "o" 's after a while but no hashing. frequency at 700 read at 10.7v. So Imagine the fix outlined in this thread isn't what I need after all?
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lightfoot
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I fix broken miners. And make holes in teeth :-)


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February 05, 2018, 11:02:27 PM
 #162

No, different problem. At this point it seems to be either a shot crystal or a shot chip. I can identify the shot chips, working on better ways to swap them out (not difficult, just time consuming)
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February 05, 2018, 11:48:05 PM
 #163

No, different problem. At this point it seems to be either a shot crystal or a shot chip. I can identify the shot chips, working on better ways to swap them out (not difficult, just time consuming)

I found replacing the chips to be the single hardest part about doing the repairs. I guess I just need a steadier hand.

Stop buying industrial miners, running them at home, and then complaining about the noise.
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February 06, 2018, 01:24:00 AM
 #164

No, different problem. At this point it seems to be either a shot crystal or a shot chip. I can identify the shot chips, working on better ways to swap them out (not difficult, just time consuming)

I found replacing the chips to be the single hardest part about doing the repairs. I guess I just need a steadier hand.
They're easier than QFN, the side power rails really help them to self-center on the pads. However did you find the bad chips using thermal imaging or something else?

And did you use air or a soldering iron?
ruinous
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February 06, 2018, 06:58:56 PM
 #165

I don't have equipment outside of basic tools for small repairs, I have a IR pen but I imagine it will take a lot longer to find a bad heat signature then with a camera. I started a thread for repair service in US. Maybe I'll get some good recommendations as a second board decided to go down now.
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February 06, 2018, 07:37:36 PM
 #166

They're easier than QFN, the side power rails really help them to self-center on the pads. However did you find the bad chips using thermal imaging or something else?

And did you use air or a soldering iron?

I found the bad chips by doing hardware diagnostics on the board. There are two heartbeat signals on the board, one going beginning to end, the other end to beginning. By using the test points on the board you can isolate the issue down to the individual chain of 3 chips. From there you can do some resistance testing and figure out which chip is shorting.

I used a heat gun and tweezers for all removal and replacement. That is how the bitmain techs do to work on the boards.

Heat em up, pull em off, tin the new chip, and drop it into place.

Stop buying industrial miners, running them at home, and then complaining about the noise.
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June 07, 2018, 07:37:57 PM
 #167

Hi all,

Has anyone found were the temperature circuit is at?

Thanks in advance
ShefSam
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June 09, 2018, 09:09:54 PM
 #168

Hi all,

Has anyone found were the temperature circuit is at?

Thanks in advance

EXCELLENT QUESTION!  Been wondering/trying to isolate for months!!!

Alms?:BTC:  1JN9gyJgpw7uYvEaV4YcwaAv1Nt146sm7
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June 09, 2018, 09:15:32 PM
 #169


Is there a definitive explanation for why hashrate will degrigdate from perfect/normal (or at least acceptable) when fans are fine, temp is fine, no chip errors, default or reasonable frequency is set, etc. et al...? Unit seems and reads perfectly fine, but cannot hold its hashrate.

Please advise.  Any way to remedy?


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