My Antminer S21+ has a problem

[xpothaha]

My S21+ device has a problem. It can only mine for about 5 minutes. After that, it stops mining.

- I tried updating the firmware.

- I tried changing the Pool.

- I tried switching the Hashboard cable.

(Switching 2-3 times, it still shows the Board 0 error.)

- I tried buying a new control board to try to replace it, but the problem is still the same.


It's a new machine that I bought about 3 months ago, but I just started using it and it still can't dig for me. Does anyone have any advice or the correct cause of the problem for me?

I think I'll have to send it for repair but in case there is a solution.

===========================================Miner log===========================================
2025-06-19 09:11:23 [INFO_] commit version: 6eae4985e2fdb7f57d8220024fe3763f6a54647f 2025-04-22 15:03:49, build by: jenkins 2025-04-22 15:23:42
2025-06-19 09:11:23 [INFO_] platform[AML]
2025-06-19 09:11:23 [INFO_] miner type[Antminer S21+] firmware type[Release] compile time[Tue Apr 22 15:05:57 CST 2025]
2025-06-19 09:11:23 [INFO_] firmware version[FR-1.15(250422-S21+)]
2025-06-19 09:11:23 [INFO_] MAC[02:85:65:DB:66:4B]
2025-06-19 09:11:23 [INFO_] work mode[NEM_MODE]
2025-06-19 09:11:31 [INFO_] power version[0x00c1] sn[KLKT335BEJAAG1084] calibrated[true] c_date[211208]
2025-06-19 09:11:31 [INFO_] framework init success
2025-06-19 09:11:31 [INFO_] power init success
2025-06-19 09:11:31 [INFO_] fan init success
2025-06-19 09:11:32 [INFO_] temp init success
2025-06-19 09:11:32 [INFO_] kill all hashboard
2025-06-19 09:11:32 [INFO_] start to check network
2025-06-19 09:11:48 [INFO_] cooling the boards, please wait, this may take up to 5 minutes...
2025-06-19 09:13:33 [INFO_] bring up temperature[36.50] diff[3.00]
2025-06-19 09:13:40 [INFO_] hashboard power on
2025-06-19 09:13:41 [INFO_] board[0]: asic num[55] times[0]
2025-06-19 09:13:41 [INFO_] board[1]: asic num[55] times[0]
2025-06-19 09:13:42 [INFO_] board[2]: asic num[55] times[0]
2025-06-19 09:16:16 [ERROR] board[0] rate[89.39] less than limit[95.00]
2025-06-19 09:16:16 [INFO_] kill all hashboard
2025-06-19 09:16:17 [ERROR] S21+ setup err
2025-06-19 09:16:17 [ERROR] ---[S21PT1_MINER_SETUP_ERR]
2025-06-19 09:16:17 [ERROR] -------[S21PT1_CONFIGURE_ASIC_ERR]
2025-06-19 09:16:17 [ERROR] -----------[S21PT1_EXECUTE_FREQ_BOOST_ERR]
2025-06-19 09:16:17 [ERROR] ---------------[S21PT1_FREQ_UP_ERR]
2025-06-19 09:16:17 [ERROR] -------------------[FREQ_UP_V1_SET_FREQ_STEP_UP_OPERATION_ERR]
2025-06-19 09:16:17 [ERROR] -----------------------[S21PT1_VOLTAGE_ADJUST_ERR]
2025-06-19 09:16:17 [ERROR] ---------------------------[S21PT1_FREQ_UP_RATE_TOO_LOW_ERR]

[BitMaxz]

If the logs you posted above is came from the new control board I suggest to put the stock back and other components before running the unit again and monitor the logs.

Post the logs again here don't forget to put it with insert code tag a # button, while editing your post.

I don't have any idea what the cause of your issue is. But I'd like to suggest try modded or custom firmware like Braiins OS or Awesome Miner firmware and then boot it via SD card.

Update here if it works on custom/modded firmware.

[philipma1957]

My S21+ device has a problem. It can only mine for about 5 minutes. After that, it stops mining.

- I tried updating the firmware.

- I tried changing the Pool.

- I tried switching the Hashboard cable.

(Switching 2-3 times, it still shows the Board 0 error.)

- I tried buying a new control board to try to replace it, but the problem is still the same.


It's a new machine that I bought about 3 months ago, but I just started using it and it still can't dig for me. Does anyone have any advice or the correct cause of the problem for me?

I think I'll have to send it for repair but in case there is a solution.

===========================================Miner log===========================================
2025-06-19 09:11:23 [INFO_] commit version: 6eae4985e2fdb7f57d8220024fe3763f6a54647f 2025-04-22 15:03:49, build by: jenkins 2025-04-22 15:23:42
2025-06-19 09:11:23 [INFO_] platform[AML]
2025-06-19 09:11:23 [INFO_] miner type[Antminer S21+] firmware type[Release] compile time[Tue Apr 22 15:05:57 CST 2025]
2025-06-19 09:11:23 [INFO_] firmware version[FR-1.15(250422-S21+)]
2025-06-19 09:11:23 [INFO_] MAC[02:85:65:DB:66:4B]
2025-06-19 09:11:23 [INFO_] work mode[NEM_MODE]
2025-06-19 09:11:31 [INFO_] power version[0x00c1] sn[KLKT335BEJAAG1084] calibrated[true] c_date[211208]
2025-06-19 09:11:31 [INFO_] framework init success
2025-06-19 09:11:31 [INFO_] power init success
2025-06-19 09:11:31 [INFO_] fan init success
2025-06-19 09:11:32 [INFO_] temp init success
2025-06-19 09:11:32 [INFO_] kill all hashboard
2025-06-19 09:11:32 [INFO_] start to check network
2025-06-19 09:11:48 [INFO_] cooling the boards, please wait, this may take up to 5 minutes...
2025-06-19 09:13:33 [INFO_] bring up temperature[36.50] diff[3.00]
2025-06-19 09:13:40 [INFO_] hashboard power on
2025-06-19 09:13:41 [INFO_] board[0]: asic num[55] times[0]
2025-06-19 09:13:41 [INFO_] board[1]: asic num[55] times[0]
2025-06-19 09:13:42 [INFO_] board[2]: asic num[55] times[0]
2025-06-19 09:16:16 [ERROR] board[0] rate[89.39] less than limit[95.00]
2025-06-19 09:16:16 [INFO_] kill all hashboard
2025-06-19 09:16:17 [ERROR] S21+ setup err
2025-06-19 09:16:17 [ERROR] ---[S21PT1_MINER_SETUP_ERR]
2025-06-19 09:16:17 [ERROR] -------[S21PT1_CONFIGURE_ASIC_ERR]
2025-06-19 09:16:17 [ERROR] -----------[S21PT1_EXECUTE_FREQ_BOOST_ERR]
2025-06-19 09:16:17 [ERROR] ---------------[S21PT1_FREQ_UP_ERR]
2025-06-19 09:16:17 [ERROR] -------------------[FREQ_UP_V1_SET_FREQ_STEP_UP_OPERATION_ERR]
2025-06-19 09:16:17 [ERROR] -----------------------[S21PT1_VOLTAGE_ADJUST_ERR]
2025-06-19 09:16:17 [ERROR] ---------------------------[S21PT1_FREQ_UP_RATE_TOO_LOW_ERR]

you seem to have over eager shut down speed.

disconnect board zero use the  white feed wire to it.see if that works.

i wish you did not rush to buy the controller.

https://altairtech.io/product/epic-umc/

https://github.com/epicblockchain/powerplay-antminer


epic allows you to shut off any board and run the other two
epic supports the s21+


braiins and vnsh may work.

[mikeywith]

This is a not-so-uncommon problem with the S21+' chassis. It's not strong enough to handle rough shipping and handling. So, it's possible that one or more hashboards were physically damaged -- not necessarily lost a chip or two, since your kernel log shows 55 chips on all three boards, but it's likely a dent somewhere that dislocated the hashboards from their original place. If you are not planning on sending it back for warranty, you may disassemble the miner and visually inspect for misaligned hashboards, such as one hashboard touching the other one/s.

[Armadatalk]

I had a similar situation  , I was helped by a person I found in telegram. Look for him by nickname @temp75

[stribi]

I have a similar issue. Can someone post the solution HERE, please. Thank you.

[BitMaxz]

I have a similar issue. Can someone post the solution HERE, please. Thank you.

Have you tried the basic troubleshooting?

Have you tried to test the unit with a single hashboard? Try to test them one by one to find which hashboard is causing this issue.

If it does not work try to flash it first with the latest firmware to test.
If flashing does not fix your issue, copy the whole logs and paste it here. We can only determine the issue if you can share your miner logs and make sure you are using stock firmware since I'm not so familiar with other custom firmware logs.

Usually, this issue is due to overheating, or maybe one of the hashboards has one ASIC chip with a loose heat sink. So try to check them visually and then update here.

[philipma1957]

yeah simply disconnect a white wire to a hashboard.

loosen the connections for the power bars to all three hashboards.

remove the 2 nuts for the hashboard you removed the white info to.

Slide a non conductor under the bars for just that hashboard.

tighten the other 2 hashboard backup.

this means one hashboard has zero power connection and zero info connection.

See if the gear runs.

do this 1 board at a time to find the bad board.

[stribi]

Thank you for your reply.
I try flash newest firmware update, dont help.

When i try unpluged one hashboard mining dont start, i dont know how to test hashboard one by one.

2025-12-27 13:34:10 [INFO_] commit version: 6eae4985e2fdb7f57d8220024fe3763f6a54647f 2025-04-22 15:03:49, build by: jenkins 2025-04-22 15:23:42
2025-12-27 13:34:10 [INFO_] platform[AML]
2025-12-27 13:34:10 [INFO_] miner type[Antminer S21+] firmware type[Release] compile time[Tue Apr 22 15:05:57 CST 2025]
2025-12-27 13:34:10 [INFO_] firmware version[FR-1.15(250422-S21+)]
2025-12-27 13:34:10 [INFO_] SN[HQDZG4UBEJBJE019N]
2025-12-27 13:34:10 [INFO_] MAC[02:87:95:A3:65:C5]
2025-12-27 13:34:10 [INFO_] work mode[NEM_MODE]
2025-12-27 13:34:18 [INFO_] power version[0x00c1] sn[DGAH347BEJBAB0714] calibrated[true] c_date[211208]
2025-12-27 13:34:18 [INFO_] only 2 boards plug in
2025-12-27 13:34:18 [ERROR] board num is not enough
2025-12-27 13:34:18 [ERROR] err code[J:8]
2025-12-27 13:34:18 [ERROR] S21+ setup err
2025-12-27 13:34:18 [ERROR] ---[S21PT1_BOARD_NUM_ERR]

This is first log after issue

2025-12-26 17:13:25 [INFO_] 30m miner hashrate[206157.21] board[0] hashrate[73881.68] board[1] hashrate[67342.03] board[2] hashrate[64933.49]
2025-12-26 17:37:20 [WARN_] power watt change too fast, last[4879] now[0]
2025-12-26 17:37:32 [ERROR] feedback voltage[0.00] allowed band max[12.99] min[10.63] status[2097152]
2025-12-26 17:37:32 [INFO_] miner restart
2025-12-26 17:37:32 [INFO_] kill all hashboard
2025-12-26 17:37:33 [INFO_] start to check network
2025-12-26 17:37:37 [INFO_] cooling the boards, please wait, this may take up to 5 minutes...
2025-12-26 17:41:33 [INFO_] bring up temperature[26.00] diff[3.00]
2025-12-26 17:41:41 [INFO_] board[0]: asic num[55] times[0]
2025-12-26 17:41:42 [INFO_] board[1]: asic num[55] times[0]
2025-12-26 17:41:42 [INFO_] board[2]: asic num[55] times[0]
2025-12-26 17:46:22 [INFO_] kill all hashboard
2025-12-26 17:46:23 [ERROR] miner restart err
2025-12-26 17:46:23 [ERROR] ---[S21PT1_CONFIGURE_ASIC_ERR]
2025-12-26 17:46:23 [ERROR] -------[S21PT1_EXECUTE_FREQ_BOOST_ERR]
2025-12-26 17:46:23 [ERROR] -----------[S21PT1_FREQ_UP_ERR]
2025-12-26 17:46:23 [ERROR] ---------------[FREQ_UP_V1_SET_FREQ_STEP_UP_OPERATION_ERR]
2025-12-26 17:46:23 [ERROR] -------------------[S21PT1_VOLTAGE_ADJUST_ERR]
2025-12-26 17:46:23 [ERROR] -----------------------[S21PT1_FREQ_UP_RATE_TOO_LOW_ERR]
2025-12-26 18:11:18 [INFO_] kill all hashboard

[stribi]

hi lads,

dont worry about the issue. I just sorted it out.
Just changed mein electricity supply cable and it works...looks like unstable voltage from outside.

[BitMaxz]

2025-12-27 13:34:10 [INFO_] commit version: 6eae4985e2fdb7f57d8220024fe3763f6a54647f 2025-04-22 15:03:49, build by: jenkins 2025-04-22 15:23:42
2025-12-27 13:34:10 [INFO_] platform[AML]
2025-12-27 13:34:10 [INFO_] miner type[Antminer S21+] firmware type[Release] compile time[Tue Apr 22 15:05:57 CST 2025]
2025-12-27 13:34:10 [INFO_] firmware version[FR-1.15(250422-S21+)]
2025-12-27 13:34:10 [INFO_] SN[HQDZG4UBEJBJE019N]
2025-12-27 13:34:10 [INFO_] MAC[02:87:95:A3:65:C5]
2025-12-27 13:34:10 [INFO_] work mode[NEM_MODE]
2025-12-27 13:34:18 [INFO_] power version[0x00c1] sn[DGAH347BEJBAB0714] calibrated[true] c_date[211208]
2025-12-27 13:34:18 [INFO_] only 2 boards plug in
2025-12-27 13:34:18 [ERROR] board num is not enough
2025-12-27 13:34:18 [ERROR] err code[J:8]
2025-12-27 13:34:18 [ERROR] S21+ setup err
2025-12-27 13:34:18 [ERROR] ---[S21PT1_BOARD_NUM_ERR]

It looks like this new firmware doesn't support running with a single hashboard. If you can boot it to Braiins OS, we might be able to spot this power issue since the stock can't work with a single hashboard.

hi lads,

dont worry about the issue. I just sorted it out.
Just changed mein electricity supply cable and it works...looks like unstable voltage from outside.

That's a good update. A thin cable that heats fast can't provide enough power, which causes this issue.
Sometimes long extension also cause this that's why recommend to directly plug the unit on the wall outlet.

[philipma1957]

2025-12-27 13:34:10 [INFO_] commit version: 6eae4985e2fdb7f57d8220024fe3763f6a54647f 2025-04-22 15:03:49, build by: jenkins 2025-04-22 15:23:42
2025-12-27 13:34:10 [INFO_] platform[AML]
2025-12-27 13:34:10 [INFO_] miner type[Antminer S21+] firmware type[Release] compile time[Tue Apr 22 15:05:57 CST 2025]
2025-12-27 13:34:10 [INFO_] firmware version[FR-1.15(250422-S21+)]
2025-12-27 13:34:10 [INFO_] SN[HQDZG4UBEJBJE019N]
2025-12-27 13:34:10 [INFO_] MAC[02:87:95:A3:65:C5]
2025-12-27 13:34:10 [INFO_] work mode[NEM_MODE]
2025-12-27 13:34:18 [INFO_] power version[0x00c1] sn[DGAH347BEJBAB0714] calibrated[true] c_date[211208]
2025-12-27 13:34:18 [INFO_] only 2 boards plug in
2025-12-27 13:34:18 [ERROR] board num is not enough
2025-12-27 13:34:18 [ERROR] err code[J:8]
2025-12-27 13:34:18 [ERROR] S21+ setup err
2025-12-27 13:34:18 [ERROR] ---[S21PT1_BOARD_NUM_ERR]

It looks like this new firmware doesn't support running with a single hashboard. If you can boot it to Braiins OS, we might be able to spot this power issue since the stock can't work with a single hashboard.

hi lads,

dont worry about the issue. I just sorted it out.
Just changed mein electricity supply cable and it works...looks like unstable voltage from outside.

That's a good update. A thin cable that heats fast can't provide enough power, which causes this issue.
Sometimes long extension also cause this that's why recommend to directly plug the unit on the wall outlet.

Well he found a good fix.

Yeah the + units have fucked up firmware which can not  do as I much. No one should be getting them.

[stribi]

interesting is when I plug S21+ back to original socket and switch off my s19pro and Z15, works fine again.
It is possible? I read something about disturbance or digital noise.