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Topic: Repairing Antminer S9j - page 2. (Read 333 times)

member
Activity: 124
Merit: 11
February 01, 2023, 03:39:23 PM
#10
All of the things that you mentioned can be replaced, especially the caps, while the cables you already replaced/fix as I can see.

Very hot caps or even MPUs that pop out on a thermal scan can indicate a short or a chip that went bad. It's a pretty common technique for troubleshooting something like laptops.

If you have a multimeter and a spec sheet for some of those MPUs that is getting hot, you could check if the voltages are correct on the pinouts.
legendary
Activity: 3234
Merit: 2943
Block halving is coming.
January 31, 2023, 07:53:44 PM
#9
I don't know what power you have in your house if it's 110v or 220v. Maybe the power source is not stable which is why it drops after a few hours and you must run this miner at 220v but if you run the miner at low power or 110v the miner will experience some issues like overheating and drops in hash rate.

I hope that you can share the kernel logs here so that we can understand what happened to your miner without them we can't just find the solution by guessing.
member
Activity: 199
Merit: 37
January 31, 2023, 05:15:50 PM
#8
Your Antminer is rebooting because of the faulty board.

You can try with only the faulty one connected to the control board and to the psu
You will see if the board is ok or not

If you can, try with an other PSU
Never use these damaged cables man, it is very risky

As you said you can still use the Antminer with the 2 good boards. Don't forget to remove the data cable between CB and faulty HB if you are doing it like that, you can remove completely the faulty board.

As BitMaxz said, you can learn how to test and fix your faulty board. Zeus website is a good starting point. If you want, I can DM you a Discord server where people are pretty efficient with hashboards repairs and tests
Thank you very much!

I spent a few hours cleaning and repairing the cables with 'liquid electrical tape' and testing the resistance / continuity of each cable.

Then I ran the miner with 3 boards in it, but the faulty one completely disconnected. I think 3 boards need to be in the housing or the airflow will bypass the remaining boards.

Then miner ran well for 3.5hrs and then stopped suddenly and completely.  On rebooting, only 1 board was still working. But the remaining board was not running properly either, so I checked the output voltage of the PSU and it has dropped to 10.8V DC (previously it was 11.98V DC) Something broke in the PSU.

A closer look at the serial numbers of the hashboards etc makes me think that the seller (or someone who sold to the seller) has put together the shittiest components from several miners and sold them on. Different amounts of corrosion on the heatsinks and 1 is not for the S9j as far as I can tell.

Anyway, next step is to connect a good PSU and check each board if it runs with that.

A link to the discord server would be great!
hero member
Activity: 504
Merit: 1065
Crypto Swap Exchange
January 29, 2023, 03:39:04 PM
#7
Your Antminer is rebooting because of the faulty board.

You can try with only the faulty one connected to the control board and to the psu
You will see if the board is ok or not

If you can, try with an other PSU
Never use these damaged cables man, it is very risky

As you said you can still use the Antminer with the 2 good boards. Don't forget to remove the data cable between CB and faulty HB if you are doing it like that, you can remove completely the faulty board.

As BitMaxz said, you can learn how to test and fix your faulty board. Zeus website is a good starting point. If you want, I can DM you a Discord server where people are pretty efficient with hashboards repairs and tests
member
Activity: 199
Merit: 37
January 29, 2023, 12:38:11 AM
#6
A little update:

When I disconnect the power cables and the control cable (or what is that called?) to the faulty hashboard, then the S9j runs continuously and the 2 good hashboards are hashing close to their expected specifications.

There are probably enough undamaged PSU cables to run both of the good hashboards with undamaged cables and make the rest safe very cheaply.

My plan is to see if I can find a visible difference between the good and bad hashboards, in case it is something easy to fix.

If there is nothing obviously fixable, then I want to try to mount only the 2 good boards in the housing and add extra heat sinks and 200mm fans at each end, and stand the miner up so that it blows out the top for some free chimney cooling effect.

Hopefully I can tame it sufficiently to turn it into a 9.6TH/s miner that can be operated with reasonably low noise levels inside a house.
Tame enough to be plugged into any normal power outlet and be turned on when the solar panels produce more power than what gets used at the moment.

I want to eventually have a refurbished miner for every neighbouring house in my area which has solar panels. Different miner sizes for different amounts of stranded energy, but maybe all of them bought dirt cheap because of some faulty boards, and then 'tamed' to be less obnoxiously loud and demanding of specialised power delivery and heat disposal systems.
member
Activity: 199
Merit: 37
January 27, 2023, 07:58:30 PM
#5
That's a good choice if the seller accepts your deal but most of the sellers if you buy at that price they do not refund or partially refund you are lucky if the seller accepts it.

About repairing it you can repair it ZeusBTC has some guide for repairing the s9 hashboard but not the whole unit.
And about replacing Hashboard on the s9 series it doesn't need to match like power or serial it is not the same as the 17 series above that requires hashboard editor to match EEPROM data like serial number and power.

About the wire, you can replace it with the same gauge or above to make sure there is no power lost or sometimes it can lead to a short circuit, or if it is replaced with a higher gauge wire it won't easily melt.

Thanks!
The seller was really quick to refund the largest part of what I paid.
64% of initial purchase price were refunded within an hour of me laying out my reasoning for why I would only pay that much if it had been listed in it's actual condition.

I'm the happy owner of a repairable wreck!  Grin
legendary
Activity: 3234
Merit: 2943
Block halving is coming.
January 27, 2023, 07:52:53 PM
#4
That's a good choice if the seller accepts your deal but most of the sellers if you buy at that price they do not refund or partially refund you are lucky if the seller accepts it.

About repairing it you can repair it ZeusBTC has some guide for repairing the s9 hashboard but not the whole unit.
And about replacing Hashboard on the s9 series it doesn't need to match like power or serial it is not the same as the 17 series above that requires hashboard editor to match EEPROM data like serial number and power.

About the wire, you can replace it with the same gauge or above to make sure there is no power lost or sometimes it can lead to a short circuit, or if it is replaced with a higher gauge wire it won't easily melt.
member
Activity: 199
Merit: 37
January 27, 2023, 05:57:41 PM
#3
Return it .
Definitely a sensible suggestion! Thanks!

But on the other hand, I like repairing things and learn a lot in the process. I think this is just the first used miner that I might eventually revive and deploy on a hunt for stranded energy. 

I'll try to get a decent partial refund and then get it into a functional state.
legendary
Activity: 4116
Merit: 7849
'The right to privacy matters'
January 26, 2023, 11:11:54 PM
#2
Return it .
member
Activity: 199
Merit: 37
January 26, 2023, 10:47:20 PM
#1
I bought a used S9j miner and it is not in good working order.

Now I am trying to decide if I should send it back or negotiate a price drop and then learn how to repair it. Any helpful hints would be much appreciated!

One of the three hashboards does not work. The red LED comes on sometimes, and sometimes a small number shows in the GH/S(RT) column, but it never heats up or produces significant hashes. Mostly it hashes zero.



The power supply has damage to multiple cables, they must have been chafing against sharp metal shelve edges or something like it.




Some of the output capacitors in the PSU seem to be getting much hotter than others, and the miner (hashing on 2 boards only) stops hashing every few minutes and starts over. I don't know if the PSU might be too weak, have not investigated in any detail yet.

Questions:
1) Is it potentially possible to repair the hashboard? I have swapped over the cables between the control board and the hash board, the fault is in the hashboard not the cable or control board.

2) Can the capacitors be replaced? It looks to me like I can solder new ones in, but I have no idea if they are hard to find, and if I would need to replace all of them instead of the 2 that look hotter on an infrared photo.

3) Could a replacement hashboard be used, or do they need to be a 'matching set' or specific serial number?

4) I think I can de-solder the cables at the PSU board and then put shrink-wrap around the damaged parts and solder them back on. Or is that a particularly stupid idea?

Thanks for any helpful hints!
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