Antminer Firmware Downloads for BTC and LTC Miners
Antminer firmware from us means Vnish custom firmware, distributed under an official partner agreement in the USA. Use v1.3.5: one build covers most models and identifies the hardware at boot. v1.2.7 remains for setups that need a separate per-model file. Both add per-chip tuning, watchdog protection and control over a degraded miner.
Which firmware for your model
Both archives below are complete packages with the installation tools included, hosted on our own server rather than a third-party file share, and they are built differently in a way that matters. v1.2.7 is the last release that ships a separate firmware file for every model — you pick the file that names your miner. v1.3.5 is the current release: one build can serve several models and identifies the hardware itself at boot, which makes it the safer choice on newer machines. It also drops some of the visual settings the 1.2 branch had. In both cases the file still has to match your control board family.
Download Antminer Repair Firmware v1.3.5 – current release, full archive with installation tools
Download Antminer Repair Firmware v1.2.7 – previous branch, one file per model
| Antminer model | Recommended | v1.2.7 also works | Notes |
|---|---|---|---|
| S19, S19 88, S19 126, S19i, S19+ | v1.3.5 | Yes | The 126-chip S19 on a Xilinx control board is only recognised from v1.3.5. |
| S19 Pro, S19 Pro A, S19a, S19a Pro | v1.3.5 | Yes | Auto-detection of the 114-chip S19 Pro was corrected in v1.3.5. |
| S19j, S19j+, S19j Pro, S19j Pro+, S19j Pro A, S19j XP | v1.3.5 | Yes | The most common family we see. Either build runs it. |
| S19k Pro | v1.3.5 | Yes | One stock build, FR-1.28 (251010-S19k Pro), blocks the normal install and has to be cleared first — ask us before you start. |
| S19 XP, S19 XP+ | v1.3.5 | XP yes, XP+ no | Air-cooled S19 XP+ support arrived in the 1.3 branch. |
| T19 | v1.3.5 | Yes | T19 auto-detection was improved in v1.3.5; older archives can misread the chain. |
| S19 Hydro family, including S19 Pro Hydro, S19 XP Hydro, S19 XP+ Hydro, U3S19XPH | v1.3.5 | Partly | Hydro sub-models were added in stages. Send us the sub-model code before flashing an older build. |
| S21, S21+, S21 Hydro, S21 Immersion, T21 | v1.3.5 | Yes | T21 ships on Amlogic, Xilinx and CVITEK boards — three different files for one model name. On Amlogic boards a recent stock build can lock the miner before you get this far: see S21 firmware unlock and recovery. |
| S21 Pro, S21 XP, S21 XP Hydro | v1.3.5 | Mostly | Some board revisions are only recognised from the 1.3 branch. Presets for these models were reworked, so retune after updating. |
| S21 Pro+ | v1.3.5 | No | Support added in the 1.3 branch only. |
| S21++ | v1.3.5 | No | Newest addition. v1.2.7 does not know this model. |
| L7 (Scrypt) | v1.3.5 | Yes | Xilinx control board. Developer fee on the L series is lower than on the SHA-256 miners. |
| L9 (Scrypt) | v1.3.5 | Yes | Amlogic and CVITEK boards. Stock build FR-1.19 (260302-L9) blocks the normal install — ask us before you start. Presets were reworked in the 1.3 branch — retune after updating. |
| U2L9H | v1.3.5 | No | Support added in v1.3.5. |
| S9, S17, S17 Pro, T17 | Neither | No | These run on a separate, frozen Vnish line with its own 2.0.x numbering. Do not flash a 19 or 21 series file onto them — ask us for the right one. |
| 23 series, L11 | Not yet | No | No released custom firmware at the time of writing. |
Two things decide the file, not one. Pick the version from the table, then pick the build for your control board family — BeagleBone, Xilinx, Amlogic or CVITEK. The slot placement identifies it: Xilinx and CVITEK put the SD slot on the outside, BeagleBone keeps it inside on the board, Amlogic has a micro USB port and no SD slot. Flashing a file built for a different board family is the most common way a working miner becomes a bench job. If the marking on your board does not match anything on this page, send us a photo of it first.
Before the first install, check what stock firmware is on the miner. Bitmain builds from March 2024 onward verify signatures and reject unsigned images, and Amlogic boards running stock firmware from September 2025 or later have the micro USB port switched off, which closes the usual downgrade route. This is the reason most first installs fail, and it is dealt with before the Vnish file is ever uploaded. On a 21-series miner that is a bench job and we do it as Antminer S21 firmware unlock and recovery. On other models, message us with the model and the stock build number before you start, and we will tell you what it takes.
What Vnish firmware actually changes
Stock firmware gives you one frequency for a whole chain and board-level averages to look at. Vnish tests every ASIC on every hashboard on first boot and then sets frequency and voltage per chip, giving the stronger chips more and the weaker ones less. That first tuning run takes about three to four hours. Afterwards you get per-chip hashrate, temperature and error counts instead of a board average.
On efficiency, the honest numbers are narrower than the marketing. Autotuning against stock is generally worth somewhere around 5 to 15 percent in joules per terahash. The large power reductions people talk about come from choosing a lower watt target, not from tuning: an S19j Pro class miner can be brought from roughly 3,068 W down to around 1,740 W, and the hashrate comes down with it. On a few models, including some hydro units, underclocking makes the J/TH figure worse rather than better. It is worth setting the target per machine and measuring, not copying a preset from a forum.
The protection settings matter more than the tuning on hardware that is already marginal. Vnish will restart on a hashrate drop with a capped number of attempts, halt mining at a critical chip temperature, shut down a board that stops responding to the integrity check, balance voltages, lower the performance profile automatically when the miner overheats or errors, and retune by itself when a chain breaks. It also has an immersion mode that disables fan monitoring and fan-dependent shutdowns, and a one-click return to stock from the miner's own menu.
Running a miner that has lost a hashboard
This is the part that matters when something has already gone wrong. Stock firmware treats any deviation on a chain as a reason to stop the machine. One board out of three failing to report its full chip chain is enough — the whole miner stands still. Not a third of the hashrate lost: all of it.
Vnish does not do that. You disable the failed board, tell the firmware how many chains are working, and the miner keeps hashing on the boards that are healthy. A three-board S21 with one dead board carries on earning at roughly two thirds of its rate while the third board sits on our bench instead of the machine sitting idle in your shed.
That is the good case, where the miner still runs. On the 21 series the stock firmware can take the opposite path: once it has marked a chain out it refuses to start at all, and there is no interface left to install anything through. If your log ends on Not enough chain, exit. or names a chain with you should send it to repair, the board is often healthy and the verdict is the problem — that is S21 firmware unlock and recovery, and it is worth settling before you order anything.
What no firmware can do is work around a dead chip. The chips sit in a chain, and a chain with a dead chip will not initialise at all — the board is either alive or it is a repair. So this is a way to keep earning during the repair window, not a substitute for the repair. A chain that has failed once does not recover on its own, and running a degrading board hot next to good ones is how a repairable board becomes an unrepairable one. When you are ready, send it in — we do component-level Antminer hashboard repair in the USA and test every board under real mining load before it goes back.
Updating firmware on the control board
Worth clearing up first: hashboards do not run firmware. The firmware lives on the control board, which is the small computer that runs the miner. A hashboard carries an EEPROM instead, holding its identity and configuration — serial number, chip count and mapping, voltage domains, frequency tables, hardware revision. When that EEPROM is unreadable the control board misreads the chain, and the symptom looks like a firmware problem while the cause is on the board. That case is EEPROM repair, not a reflash.
For the control board itself there are two routes, and they are not interchangeable:
| Web interface upgrade | Flashing the control board | |
|---|---|---|
| Where it happens | The miner's own System > Upgrade page | From an SD card or over USB, at the board |
| Miner has to boot | Yes, and be reachable on the network | No |
| What it writes | An update package on top of an intact bootloader and root filesystem | The whole stack, bootloader included |
| Signature check | Enforced on recent stock builds, which is what blocks downgrades | Bypassed on most generations, where the port is still open |
| File | Web update package | A full board image — a different file entirely |
Which route applies to you is decided by the control board family. Amlogic boards take the file straight from the miner's interface. BeagleBone and Xilinx boards have historically needed the SD route for a first install, and the SD image is not shipped with every release, so ask us which image goes with your board rather than assuming the archive contains one.
If the miner no longer boots at all — no interface, no IP, no response to the IP reporter — that is past the point where a firmware page can help. One fork before you go further: on a 21-series miner the same silence is very often the stock firmware refusing to start after it marked a chain out, not a dead board. If the last thing in the log is Not enough chain, exit., start with S21 firmware unlock and recovery — it is the cheaper question and it settles the expensive one. Otherwise nobody can tell from a description whether it needs a restore or a new board, and that is a diagnosis, not a download: start with Antminer control board replacement.
Fees, warranty and what can go wrong
This firmware carries a 3% developer fee. It is taken as hashrate redirected to the developer pool while the miner runs, not billed to you, and for most operators it is covered several times over by the electricity saved. We state it here because a firmware page that leaves the fee out is hiding part of your cost per terahash.
On warranty, Bitmain's position is unambiguous: installing unauthorised third-party firmware voids it. Vnish can be rolled back to stock from the miner's own menu, but a rollback is not the same as the warranty surviving, and on recent Amlogic boards running security firmware the downgrade path may be closed to you. If a miner is still inside its warranty window, that is a real cost to weigh, not a formality.
The other honest risk is the install itself. An interrupted write — power cut, storage device pulled, cancelled halfway — can leave the control board without working low-level software, and at that point it is a service-centre job rather than something you retry. Pushing voltage and frequency hard also trades chip lifespan for hashrate; sustained high temperatures shorten it measurably.
Disclaimer: We are not responsible for any issues resulting from firmware installation if it is performed by third parties or not according to our instructions. Installing third-party firmware may void your factory warranty.
5% repair discount after 30 days
Run our firmware for 30 days or more and your next repair with us costs 5% less. The condition is simple and we check it ourselves: the miner log has to show the first launch date of our firmware at least 30 days before the repair request. Mention the discount when you send the request so it lands in the quote rather than as a refund afterwards.
The reason it exists is worth saying plainly. Our logo is in the build, so when something does go wrong on a miner running our firmware, you already know where to send it — and we would rather that be a discounted repair than a search engine result.
Prefer we do it?
If your miner runs normally and you would rather not do the first install yourself, Remote Miner Diagnostics and Firmware Upgrade is the paid service for it. We connect to the miner, confirm the model and the control board family, install the correct build and set a tuning profile that suits your cooling rather than a preset copied from somewhere else. For background on what tuning is worth on a specific model, we wrote up the S19j Pro custom firmware case in more detail.
That route needs a miner we can reach. If the stock firmware has already locked the board — nothing you save is kept, or the miner will not finish starting — there is nothing on the other end for a remote session to work through, and no amount of network access changes that. On the 21 series that is S21 firmware unlock and recovery, and it is done on the bench.
Downloaded it. Now what do all these screens do?
The interface that comes up after the flash is Vnish's own, and the archive does not explain it. We put a working S21 Pro on the bench, captured every screen of v1.3.5 and marked up every control on them: the Vnish interface, screen by screen. Click the menu and the tabs inside the screenshots and the guide follows, the way the miner does. Real screens with the pool details blanked out rather than a written summary, and that includes the log tabs, where a failing chain is usually visible long before it shows up as lost hashrate.
Contact
Not sure which file you need? Send us the model and a photo of the control board marking and we will tell you which build to use. Message us on Telegram, on WhatsApp, or through the form on our contact page. You'll be chatting with a real person, not a bot — we respond during Florida daytime hours. If it's night here, replies may be delayed.