lost chain in hash borad of t9+

[zeitun]

hi
when i connected t9+ , i see one of the chain of hash board work with 12 asic inseat of 18
I need to learn  how about can i repair hash board of t9+ ,I see the below video from s9+ and i know they are have Differences,
and I know all of the asic have a common ground in bottom side of board (an other side of that put asic)
but I measure resistance in test point on hash board and I have  big Difference between asic test point for example I see 3.6 ~4 M ohm in (co,bo,Ri ) whice value is right?
and ~10m ohm in clk and 1k in reset
and see voltage in diode mode of multimeter and I test like video way but for Ri I use same gnd and same heat sink I see same voltage when  change negative and postive porb in diode test

can you help me how can i repair it? and I have true way or not to test
https://www.youtube.com/watch?v=yAiaHwRkrC4

thanks for your guidance.

[BitMaxz]

Sometimes it's not a hardware issue you should check the temp first or fan speed and maybe it is because of high temp and low fan speed that is why you are getting low ASIC chips. So increasing fan speed or reducing frequency might solve your issue.

Try to troubleshoot first if which hashboard is defective or having 12 ASIC chip.

You can check this troubleshooting guides below.

- https://support.bitmain.com/hc/en-us/articles/226142788-Test-hash-board-one-by-one
- https://support.bitmain.com/hc/en-us/articles/220872007-Possible-problems-and-solutions-for-S7-S9-fixed-frequency-L3-

And read this under troubleshooting
https://support.bitmain.com/hc/en-us/articles/360000208313-Antminer-T9-

[Artemis3]

I just (physically) opened one yesterday but was puzzled at its funny reporting. Is this a common T9+ occurrence?



Physically they are just like the S9s, just 3 asic boards. Why does it report like this? Even with separate temperatures?

[mikeywith]

Sometimes it's not a hardware issue you should check the temp first or fan speed and maybe it is because of high temp and low fan speed that is why you are getting low ASIC chips. So increasing fan speed or reducing frequency might solve your issue.

That's true , however based on my personal experience,  if the chain is not showing at all, then there is a good chance that it's a software related issue, however when the chain does show up , but the number of chips reported is lower than average then i'd say 9.9 out of 10 times it's a hardware issue.

OP , changing a chip on those boards is not something you can learn from Youtube, unless you already have an intensive experience in fixing other types of chips, also economically it does not make sense to get all the tools and probably spend 1-2k for a course to learn how to fix those boards only to fix a few potential bad hash boards you own.

if i was you, i would follow Bitmaxz advice, maybe also swap PSU cables as well as data cable, and if all that fails, i would either leave it as is, or buy another used board.