It is neither.
Perhaps reading the 1st post where how the pool operates is described would help?

You have read the various about Antminers and esp. one regarding the S17 to know that all Antminers go through an autotune process when they are powered up right?.... It can take anywhere from several min to around a 1/2hr for them to figure out optimum voltage & speeds before they start hashing on your pools.

The only possible damage would have been to the PSU with blown input rectifiers or soft-start thermistor. Frankly I am surprised the PO was able to run it at all (did they say it ran?) as the PSU should have shut down/not started at that low voltage. I'd plug it into 240VAC and see if it runs.

AFAIK no miner is double insulated. Frankly, just make sure you have a solid connection to the power distribution PE ground and that your neutral is solidly bonded to it. Do that and you are good using a normal class-C or D thermal/magnetic breaker.

Merit given to OP so they are now at 100 

Interesting, what model did you get? Did you even talk to your distributor or Canaan about it?

I and many others have the exact opposite results. I *used* to run BM gear and up to the s4 they were great, come s5 on up lots of issues culminating with all 4 T9's and 15 S9's I had each losing multiple boards. Initially repair service from Bitmain and then through Denver-based BitmainWarrenty was decent but quickly went to hell in a hand basket.

Switched to Avalons starting with the A721 and have not looked back. Currently running just over 500TH of Avalons ranging from A841's to the A1047's and aside from losing 2 fans on my oldest and now retired 721's ZERO problems.

You will find that the few folks here who did report problems were taken care of quickly and in a professional manner either by the distributor or Canaan directly. The miners are modular and easy to troubleshoot, find the problem and Canaan will get replacement parts right out to you.

I'll take 34 if still open
Thanks for the heads up Phil,
Cheers!

As Stryfe said - we have asked for proof in the other FW threads as well. No responses at all or deleted. I will say that it is heartening to at least have a response from you even if it is rather negative... The folks behind Braiins certainly do deserve Kudos for it being Open Source complete with the availability of all source code as required per the cgminer license. You are the only aftermarket firmware group do do that  

Regarding

Mostly right but not entirely accurate. Up to Canaan's A10 series their code is freely published in Github repository. From A10 on up - not sure since they have completely revamped their firmware & software but odds are it *is* available. Then again, since Canaan (up to the A10x) has the cgminer More Options field in their GUI it (was) simplicity in itself to tweak their miners to your hearts content which negated any need for aftermarket firmware...

Never said that Braiins is only used on Slush (and yes it is banned on Kano), was just saying that with Braiins being part of the Slush family, it should be easy for you folks to check how it performs.

My point was that Slush (and other pools) can easily log what FW is in the miners. As they are the ones behind Braiins they should have a vested interested in how it performs and are in the best position to verify it has no problems. I know that Kano periodically checks what FW miners are using because Kanopool (and all other small pools) does not have the hash rate to risk *any* chance of missing a block due to a bug. If the other small pools don't care - well, that's entirely up to them and is just another reason I don't mine elsewhere.

 For pool operators, when a miner finds a BTC block, query the logs to see if it runs Braiins, if it does - let folks know about it. On the actual miner side - especially large farms - the cgminer API has a block found function: Setup your monitoring software to flag it. If a non-oem miner finds a block - and any large farms should find several in a very short period of time - lets folks know! I would think that large farms should not only be checking their hash rate vs income but also be very interested in the "how many blocks did WE find and which miner did it" metrics.

Oh, and yes, the chance of any one single piece of hardware finding a block has always been slim and barring a drop in diff will just keep getting harder. But since 2014 I've found 15 blocks and over the course of 125 miners ranging from S1-S9, an uber rare AMT A1 miner circa 2014, several Avalons from 721-841, and Whatsminer M10's at least 1 from each family has found a block. I have an R4 that has found 2. The only miners I have that have not yet found a block are 2x A941, and 5x A10's. I currently run 25 miners and found Kano's last block with an A841 cluster of 5. Point is that given a large sample of miners running and provided they bother to check, a person/company *will* find blocks with their hardware giving them (and us if they share) data as to what works and what does not work.

Again, I have no animosity towards the Braiins devs and do respect you for fulfilling the cgminer license. But as an example, in the Genesis mining kerfuffle obviously shares from them were accepted by Slushpool as normal and yet there was a precipitous and lengthy drop in the farms find rate due to a bug in the proxy software that Genesis was testing. As in despite running over 300PH Genesis suddenly went from several blocks per day to zero for over a month and until other folks started bitching about the pools Luck and their income dropping apparently no one noticed something was wrong somewhere...

I and others would just like to see proof that nothing was inadvertently broken.

So far I have not seen hide nor hair of any proof that Braiins - or any other non-OEM firmware -finds BTC blocks. Considering that it is Slush who is behind the FW and no doubt there are a lot of Braiins users on Slush one would think that it would be very very easy for them to post proof it finds BTC blocks...

But so far <sound of crickets>

Brain fart - wrong pool.  post deleted.

Well hell, their 7 day hash rates tells ya more than that, "hashrate7d": "432T"

Damn straight it would because you have in effect cut the number of miners by the same percentage. That in turn is highly unfair to those running legit (known working OEM) firmware because pool payouts have to be shared with the miners running crap firmware. Again, I'm not saying that the various flavors of modded FW out there are crap but rather that the onus is on the devs of said FW to PROVE that they did not screw things up.

Mega pool operators may not mind too much because enough blocks are found per-day by the other miners to keep folks happy but for small pools missing blocks can be the Kiss of Death. That is the sole technical reason why Kano.is bans non-OEM firmware. Once someone provides verifiable proof their FW finds blocks at a rate which is on-par with OEM FW that would just leave GPL license violations as a moral reason to ban it.

Um, the find time had to be within the target of 10min average per block... You don't get work for 1 block and just keep plugging away at it, the work changes with every block found.

Some pool operators need to chime in on this but AFAIK, getting shares accepted is only part of the proof. Latency between getting/sending shares, # of rejects, stales and other things have to factor in as well. Again the FUP that Slush had a couple years ago with a VERY large miner being paid $$$ for over a month of bad work caused by a screwed up proxy comes to mind.

Considering that the devs have often stated that some large farms use the modified FW it should be a piece of cake to get proof. Heck, I only run just over 1/2 PH and to-date have hit 10 blocks on Kano.is or roughly 2 per-year since I started running there. Very large farms should be popping blocks left and right and considering most run some sort of monitoring software (or damn well should be), just set it to look for the block found flag and log it.

Considering that the cgminer API even has a report found block function, one does have to wonder just why not a single person has bothered to post anything proving said modified firmwares actually finds BTC blocks.

Hell, monitoring software like AwesomeMiner lets you set a trigger - Detect found blocks - to log it and notify ya. If folks are so fired up about using all these FW's then take the time to PROVE they work!

The author of the article is just stating the obvious. Of course the vast majority of machines never hit a block, one might as well state that in any given year 98% of people buying a Lottery ticket every day never win a significant prize. It's how the systems work: If too many win (find blocks) the system goes bankrupt so yes, the odds are stacked against players/miners. Duh!

In my case, since Feb 2014 I've owned a total of 108 miners. Most are of course now offline & replaced by faster gear as the years went by leaving me now running just 26 much faster miners. Using all that gear, to-date I've hit a total of 13 blocks while using pools - 3 at BFL's old EMC pool and the remaining 10 all on KanoPool.

Obviously most of my miners never hit a block before being replaced. BUT -- I have a 'Lucky" R4 (still running) that has hit 2 blocks both last year, 1 out of my 3x M10's hit one and 3x Avalon 841's each found 1. On Kano the remaining 4 blocks were found by various flavors of Ants from S3-S9's. All in all I think I am well ahead in terms of # of miners vs blocks found.

Along those ^^ lines, good article on crypto & the IRS - your 1040 Individual Tax Return now specifically asks if you have crypto transactions.

A key point is mentioned at the end of the article (emphasis mine)

No.
Miners have no circuits for reporting current draw and without that 1/2 of the equation (W=V*I) they cannot report power usage.

edit: As Artemis says lower on, any firmware that does give watt or Joule readouts are doing it based on the devs testing gear at various speeds/freq/temps to find typical power usage with those settings. From there is just a matter of them guess.., er, extrapolating results from where you have the miner set.

This thread is for the 921, you were discussing the 841.
Yes the commands for them are similar but - for many of the commands the values that the commands accept are different eg:
-avalon8 (or 9)-voltage-level and voltage-level-offset and the -freq values. Those have different ranges and step values that they will accept.

The 841 thread covers all of the commands and values that the 841 will accept. Here are ones in that thread from Phil

Ta boot, several of the 841 commands seem to have no effect on the 921 so....

Why is this in the wrong thread?
Should be in the 841 thread unless you have confused a 921 with a 841... Requested mods to fix that