Prewarm hashboard - to repair hashboard?

[kungen12321]

Hi Guys!

I had some bad hashboards from the antminer 17-serie layinga round. I got a tip to prewarm the bad hashboards in the oven and then quickly put it back in the miner.Believe it or not, some hashboards started to hash once again and done that for 7 straight days.

I then turned off the some off those miner and back on again. Now the miner can`t find the "broken" hashboard. So I prewarm them again and they started once again to hash.

How does it come, what conclusion is there to take?

Thanks in advance!

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[NotFuzzyWarm]

An oven is overkill. Use a hairdryer instead so you you do not have to remove the boards.
Only 2 reasons for needing to do this: Possibly a bad solder joint and heating the board makes it expand just enough to make contact - though odds are it would still be erratic.

More likely is that the board has some 'bottom of the barrel' grade chips in it and they need to be warm before they can run at whatever voltage/frequency is being commanded. The characteristics of semiconductors changes rather dramatically depending on their temp. This is why most miners do a preheat cycle when they are powered up. In your case the chips just do not get hot enough to work.

[BitMaxz]

This common issue even on other units like cellphones, laptop boards, or other boards with ICs reheating or reflowing with a BGA hot air sometimes fixes the issue like the above said it's due to bad or cold solder joints that is why reheating the hashboard will fix this issue but it is not for a long term solution.

Better find the components that cause this issue I suggest starting from the terminal/plugs and maybe it's not soldered properly.

[mikeywith]

That's like putting your miner on a ventilator, it will be a matter of time before they fail again, in fact, you could do the opposite and you would still have a good sucesss rate based on my own personal experience, put the bad hash boards in the freezer (in a sealed plastic bag of course) and many of them will run fine for a few days, I hope I will turn out to be wrong in your case, but those 17 series are TRASH.

What NotFuzzyWarm explained seems to make sense, I am not an electronic expert but I can tell you what causes 99% of the issues for those trash miners, it's the solder that keeps the chips attached to the PCB, greedy bitmain seems to have accepted the lowest bidder and made zero efforts in testing the quality of that medium-heat solder, some people also claim that the robots that did the job were also bad, but what we know for sure, the solder causes the problem in many different ways.

You will find solder balls shorting the chips, chips that lost some part of that solder underneath them so some legs are not in contact anymore, and all sorts of other things that bad solder/soldering leads to, so I am guessing that another reason in addition to what NFW mentioned is the fact the putting those hash boards in oven might have melted a solder ball that was shorting the chip and it fell off somewhere where it isn't causing an issue anymore, which is great news assuming that no other solder balls appear somewhere else.

But what you doing is great, try to fix those trash miners at the cheapest cost possible because they are not worth it.

[kungen12321]

An oven is overkill. Use a hairdryer instead so you you do not have to remove the boards.
Only 2 reasons for needing to do this: Possibly a bad solder joint and heating the board makes it expand just enough to make contact - though odds are it would still be erratic.

More likely is that the board has some 'bottom of the barrel' grade chips in it and they need to be warm before they can run at whatever voltage/frequency is being commanded. The characteristics of semiconductors changes rather dramatically depending on their temp. This is why most miners do a preheat cycle when they are powered up. In your case the chips just do not get hot enough to work.

Hello!

Thanks for the explanation! Good tip, will try with a hot air gun instead of heating them in the oven. What temperature is optimal to heat them up to? It cant get too hot, 85 degrees is the critical temperature in the Braiins software right now.

[kungen12321]

This common issue even on other units like cellphones, laptop boards, or other boards with ICs reheating or reflowing with a BGA hot air sometimes fixes the issue like the above said it's due to bad or cold solder joints that is why reheating the hashboard will fix this issue but it is not for a long term solution.

Better find the components that cause this issue I suggest starting from the terminal/plugs and maybe it's not soldered properly.

Thanks Sir! Have a better understanding now. Good tip about checking the terminal/plugs, I guess the one`s that are connected with the data cable (2x19 pin) from the control board?

[kungen12321]

That's like putting your miner on a ventilator, it will be a matter of time before they fail again, in fact, you could do the opposite and you would still have a good sucesss rate based on my own personal experience, put the bad hash boards in the freezer (in a sealed plastic bag of course) and many of them will run fine for a few days, I hope I will turn out to be wrong in your case, but those 17 series are TRASH.

What NotFuzzyWarm explained seems to make sense, I am not an electronic expert but I can tell you what causes 99% of the issues for those trash miners, it's the solder that keeps the chips attached to the PCB, greedy bitmain seems to have accepted the lowest bidder and made zero efforts in testing the quality of that medium-heat solder, some people also claim that the robots that did the job were also bad, but what we know for sure, the solder causes the problem in many different ways.

You will find solder balls shorting the chips, chips that lost some part of that solder underneath them so some legs are not in contact anymore, and all sorts of other things that bad solder/soldering leads to, so I am guessing that another reason in addition to what NFW mentioned is the fact the putting those hash boards in oven might have melted a solder ball that was shorting the chip and it fell off somewhere where it isn't causing an issue anymore, which is great news assuming that no other solder balls appear somewhere else.

But what you doing is great, try to fix those trash miners at the cheapest cost possible because they are not worth it.

I am very aware that 17-serie is trash compared to 19-serie. After 1 year of constantly failed 17-serie miners. Thanks for the tip, will try to freeze the hashboard down before starting them up. Lets see my result.

You are right. I am trying in the cheapest ways make those miners alive again.

When I buy and receive a broken 17-serie miner. I do the following steps on each hashboard.

1. Use compressed air to take away all the dust and dirt.

2. Cleaning with alcohol.

3. ultrasonic cleaning with distilled water and 10% Emag EM303 Reinigungkonzentrat Platinen 500ml. Runs 5 minutes on each side with a temperature of 50 degrees.

4. Rinse off the hash tables with distilled water.

5. Soak them in alcohol and blow them dry with compressed air.

6. Put them in the oven at 70 degrees for 20 minutes.

7. flash eeprom with pickit 3.5


More than willing to receive more tips on how to cheaply repair/get alive of broken 17-serie hashboards.

Maybe some step I'm doing wrong, like wrong temperature, degrees, liquids...? I am far away from an expert, just taken som tip here and there.


Thanks in advance!

[mikeywith]

I explained what causes the majority of issues on those Antminer 17 series in the previous post, now check that against the points you listed, and you will see that most of them will not solve the issue and will be a waste of both time and money.

Point 1 is good for anything you buy used, point 6 is good for dead hashboards as per your own experience, and point 7 is only needed when an error that matches eeprom shows up, otherwise, it would be a waste of time.

Now if I have to give you a better tip than all, it would be "do NOT buy any 17 series at all", Now if you are willing to invest time and money to learn how to fix those boards, go for it, you buy cheap broken 17 series for the $100  range, fix them, then either use or resell them, but if you are like me and "can't fix shit", the best thing would be to steer clear from that model.

[hZti]

An oven is most likely an overkill as it was said above. The same goes also for a heat gun and I am very skeptical about this advice. For one the heat gun can actually reach temperatures that are higher than the temperatures of an oven and secondly it does simple not correctly solve the issue.
The issue is the bad soldering of the chip, that will loose connection, because the lead free solder will break over time. Yes if you heat the solder over the melting point you can actually reconnect the solder if you are lucky, but you will also probably damage some components.
Still I have actually done the oven method, for one simply reason: I did not have the time or tools for a correct repair. Since the only option then was for me to throw the hardware away, I tried the oven method. It did actually fix the issue for some weeks and that was the only thing that I wanted.