S9 Hashboard diagnosis help

[dext0rb]

I am starting to learn how to fix these boards, hope this is the right subforum

I'm hoping someone can give me a pointer where to look next. I feel like something is messed up with a 1V8 line *somewhere* but I can't really pinpoint it.

Symptoms (Hashboard 63 V1.9) :

• Board is not detected - I believe the kernel log showed "can't find sensors" and it hangs there.
• I measure .772 V to the base of Q86 (The 1V8 -> 3V3 level shift transistor for RX)
  This is ~1.7 V on a good board.
• Audible clicking from the power supply section. (Assuming one of the switching supplies - but don't know which.) Both 14V (14.32) and 9V (9.2 V) appear.
  Makes me believe something is loading a supply somewhere.
• I am reading .464 V on the RI testpoint near IC 2. (The third one in the chain - on what I believe is the 1st voltage domain).
  

  IC	Good	Bad
  0	1.6 V	0 V
  1	1.6 V	0 V
  2	2 V	.464 V

Does this pinpoint IC 0 & 1 as dead? When I compare RI resistance to ground I get roughly 200k on both good and bad.

Side question: Where the heck is 2V5 generated?

thanks for any nudge in the correct direction

[1715643562]

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[1715643562]

1715643562

[dext0rb]

After more investigation:

It seems the last 5 voltage domains look more functional, and those are the ones powered off what appear to be separate regulators.

Looks like i gotta rip off some heatsinks to investigate further.

i pulled off all the heatsinks
that was some HOT fun. now i can understand the design & layout much better. i also pulled off the first 2 ASICs, that I thought were maybe shorting something to ground, but that did not help.
the buck/boost still makes noise. more investigation.

Just out of curiosity, how many versions of the S9 hashboard are there?

Edit Update: Found one of the 1V8 regulators putting out 1.5V and pulled the ASIC near it, and that seemed to make everything happier. No more noise from the switching supply. Now I'm debating if i want to put new BM1387 on there or just chalk up the board for more experimentation.

[mikeywith]

Just out of curiosity, how many versions of the S9 hashboard are there?

S9 , S9k , S9i , Sk , S9E each of these have different "looking" hash boards, I am not sure about the structure design and current flow but these are different from one another when you simply look at them with your bare eye, in fact even the S9 itself has 2 different hash boards.

But as far as Chips are cornered, here is how they are grouped.

S9 and S9i > same chip
S9j  > own chip
S9k > own chip
S9E > own chip

as for the last two , someone mentioned that both have the same chips, but I am not sure, the boards look completely different, heat sinks on the S9E look fairly large , which makes me think the chips are different , unfortunately the last two models are pretty new to the market and I doubt anyone has gone to the extent of changing a chip on them.

that was some HOT fun. now i can understand the design & layout much better...

Talk about design, I got something for you.



The above diagram explains how the signal follow within the hash board, it should give you a better and simpler understanding , if you have problem determining what the colors stand for, feel free to ask and I would explain.