Hi all!
I've 10 antminer s5 and 4 s7 miners. I think mining is interesting and it's good hobby for me.
4 antminer s5 hashboards (v1.91) failed, they went only 4 months. I bought them directly from Bitmaintech. Temperature and power is optimal in my mining room. My 20% percent breakdown ratio is very frustrating. What is you experience about s5 failure frequency? (Power and internet connection is very stable.)
I decided that I'm going to figure out how can I fix them. Of course there is no official service manual
(the BM1384 chip pdf
https://bitmaintech.com/files/download/BM1384_Datasheet_v2.1.pdf is very short-spoken).
I know the ASIC chips are in a chain and I believe that they not fail simultaneously. I suspect if there is a problematic chip in the chain the board aren’t able to hash, so I have to find the bad ASICs and I have to shunt out somehow.
I know that on a perfect board there is 0.81 V on the big black capacitor which lays between 2 ASICs and on a failed board I measure different voltages 0.3 - 1.3 on these capacitors (eg. 0.81V on 12 and bad voltages on 4). My theory is that where is not 0.81V on the capacitor there can be te failed asics.
If somebody find and separate a bad ASIC please write about it.
I know there can be several other reason for not hashing but I believe that there are only a few typical problems which occurs the symptom which can be read on many topics (no hashing and '-' at Asic status). Some of my board there is 'o' at status but not hashing and the red led illuminates so I think that boards have another type of problem. I decided to figure out the reasons of the malfunction and find mending solutions.
Any information could be helpful!
I've ordered a 500Mhz oscilloscope to better understand how a hashboard function, I'll write my finding about the theme.
I haven’t find any detailed descriptions about mending if there is please send me! Thanks all!