If you are going to use a used miner we can't say if it can mine stable or if it has some defects unless if you buy them directly from the manufacturer.
Also, Innosilicon has some bad support so I don't think it's a wise decision to buy that miner.

About the profitability of 15% per month since we are in a bear market I don't know if you can still get that 15% every month.

Try to contact offordscott he might be able to help you what is best option to buy.

Try to refresh the miner's ASIC chips through the FMS tool you can download it from this link below

- https://canaan.io/wp-content/uploads/2020/03/FMS_V2.3.3_Windows.zip

And then look for the aging tab and select any hashboard with high ASIC chip temp.


If it still overheating manually set the fan speed to 100% to test if it can help to cool down those chips

This is why I always tell newbies to buy directly only in manufacturers or authorized/verified distributors dealing with unknown sellers like AKMiner will lead to some problem or being scammed.

Do they tell you that those miners that you buy are brand-new?

Actually, it's your fault why did you buy miners on non-authorized or verified sellers?

Next time if you are going to buy a miner please use this list here https://bitcointalk.org/index.php?topic=5045732.0

Or try to contact offordscott to help you buy legit units.

Check Coinex.com you can trade there without KYC just don't forget your password because if you forgot they will force you to verify the KYC just like what happened to me last year.

Take note to those who don't know Coinex exchange is owned by ViaBTC which is a well-known pool operator. And their withdrawal limit is around 10,000 USD in any crypto or Bitcoin.

The image is still fake he only mined 3 blocks with a 50BTC reward each but the total amount balance is 312550?

If you can share your client's BTC address here we can analyze or check the address if it has a balance or do what the above suggestion you can check it by yourself.

Another thing that I notice is the color of the Bitcoin core wallet. It seems the wallet from the screenshot is edited or a modified version of Bitcoin core.

Can you try to check the Bitcoin data folder and maybe you created two wallet.dat with different names.

The default can be found here C:\Users\YourUserName\Appdata\Roaming\Bitcoin or open run and type this %APPDATA%\Bitcoin
Then look for the wallet folder to check if there are other files or make a screenshot of that folder. Let see if you created other wallets with another name.
If I'm right you can open it again with Bitcoin core to find the exact wallet.

This error "Invalid private key encoding (code -5)" usually popups if the private key has a missing character or has a compatibility issue but since you dump the private key on the same version maybe you copied the private key with a missing character. It's just my guess.

Request for a non collateral loan
Required USDT Amount: 0.01BTC
Estimated Loan 1 or 2 months
BTC Address : bc1qptg5vvtmwwgn96qgwgalpflqjvxxmvlwmu8529

Someone share it here so credit to him and this command is not permanent you can just shut down the miner and run it again or replug the miner from the outlet the settings will revert back to the original settings.

Or if you don't want to shut down the miner you can change the fan-spd to 0 and I think it will switch back to auto.

Well if the multimeter shows 8.8 volts it's not enough to run the miner check the input may be the stabilizer you talking about is not giving enough power.
This miner must be run at 220v lower than that it won't mine properly.

What is your wall voltage? Why don't you just directly plug it on the wall outlet?

If you still looking for more technical and development about Bitcoin and crypto check these links below

- https://github.com/yjjnls/awesome-blockchain/blob/master/BitCoin/awesome.md
- https://github.com/yjjnls/awesome-blockchain
- https://github.com/hitripod/awesome-blockchain

And this is the original source that includes how to build a DIY blockchain for Bitcoin.

- https://github.com/openblockchains/awesome-blockchains

Another PDF source you can read this one
- https://unglueit-files.s3.amazonaws.com/ebf/05db7df4f31840f0a873d6ea14dcc28d.pdf

Do you have any installed VPNs and running in the background?

If the captcha is Google it will challenge you to solve the captcha but sometimes it won't work due to VPN so if you have running VPN try to disable it and login again on Nicehash.

Another solution is to clear your browser cache and history or just cache only then try again.

And the last thing is go to internet option and the advanced tab and then restore advanced settings. After that click the reset button and check the personal settings and press the reset button again.

Then try to login again on nicehash let see if it fixes your issue.

Yes, this is fake and maybe it is a modified bitcoin core anyone can make a coin because Bitcoin is open source.

Another thing it might be a self-hosted node install on localhost where you can mine 50 rewards for every block you mine or maybe the image above is edited.

Why not ask the client and post the BTC address here and let us check if it's true or not. If it's true then we can provide a few suggestions to recover those BTC.

Just keep monitoring your miner and keep your miner lower than the recommended PCB temp according to the link you provided above.
S19 pro has PCB max. 80c more than that it could melt or damage some parts or ASIC chips.

If you can afford to pay much for Electricity you can install AC but actually, for me, it's not necessary to buy AC if you want to cool them down you should set up your room with proper room airflow you must have an intake fan(Air from outside) then exhaust(to exhaust hot air) you can also separate them hot and cold air you can check the link below as a sample.

- https://bitcointalk.org/index.php?topic=5263722.0

Other versions of FMS don't have an aging button there are two FMS v2.3.3 the one is the app version that doesn't have an aging button. You can find that button in the FMS v2.3.3(batch version) you can download it on Canaan technical support.

Or check this link below to download the batch version.
- https://canaan.io/wp-content/uploads/2020/03/FMS_V2.3.3_Windows.zip

Do you have any other backup from 4 different locations?
I mean other files on that 4 location as you said.

Because If you created a wallet last 2013 there is another file being generated after you created wallet from blockchain.info it's called wallet.aes.json if you have this file you can decrypt it to get your wallet's private key or something useful to recover your BTC.

It was a long time ago they planned to implement Bitcoin as another payment method but still, they didn't add it to their platform.

Check this thread https://bitcointalk.org/index.php?topic=169711.0 posted 2013

So I think it is another bluff or maybe they are going to make their own token based on what Chesky tweet above.

They also have AirBNB community and talk about accepting Bitcoin last 2016 but still, they didn't accept Bitcoin.
Look at the thread here https://community.withairbnb.com/t5/Help/Bitcoin-payment-option/m-p/141893

Let's hope they are going to accept BTC this year if not, this is another bluff.

Unlike 9flats which is their competitor before they are accepting Bitcoin as another payment option since 2013.

Since you are trading with BTC-USD pair then only watch BTC-USD pair with Tradingview like the above said USDT is much volatile compared to USD.

The only problem Tradingview doesn't have Robinhood exchange.

On the web UI just go to advanced option and look for API logs if you don't know how to go to Hagssfin guide from this link below

- https://bitcointalk.org/index.php?topic=3224256

You can also follow his troubleshooting guide under that link to help you troubleshoot the problem.

Have you tried to check the description logs on Canaan to help you analyze or troubleshoot the API logs?

Download it here https://canaan.io/wp-content/uploads/2020/03/log-Description.pdf

According to your logs under this ECMM[1] your MM board might be a problem or have poor contact between the MM board and hashboards.

I don't see anything else from the logs you didn't post the whole logs. You can copy the whole logs again and paste it to pastebin.com if you have a limit posting it here.

It's a temp of the PCB or the hashboard and the ASIC chip itself has its own temp sensor.

You can use that link as your reference you can find the PCB temp under the miner status.
And this is the sample image below



Temp(PCB) this must be what you talking about. It has a 4 PCB temp sensor as you can see from the image above. Those sensors are under the heat sink look at the image below