Antminer control board repair is not what fixes a dead controller: it is replaced, because a tested board costs less than bench time on a broken one. Which board you need is set by the family in your miner, not by the model on the sticker — Xilinx, CVITEK, Amlogic or BeagleBone. Read the marking on the main chip.
A control board is the small computer that runs the miner: it boots the machine, drives the hashboards, serves the web interface and reports to the pool. Bitmain has fitted four different families of them behind the same model names, they are not interchangeable, and writing the wrong family's firmware onto a board kills it outright. This page is the map — how to tell which one you have, which miners carry which, and where each replacement lives.
Which control board is in your Antminer?
Two checks settle it and neither needs a meter. Look at what sits beside the Ethernet jack, then read what is printed on the largest chip on the board.
| Family |
Card slot |
What the main chip says |
| XIL — Xilinx |
On the front panel, beside the Ethernet jack |
XILINX, ZYNQ and a part number starting XC7Z
|
| CV — CVITEK |
On the front panel as well — indistinguishable from Xilinx from the outside |
CVITEK CV1835 |
| AML — Amlogic |
None at all. A micro-USB port sits there instead |
AMLOGIC A113D |
| BB — BeagleBone |
Inside, on the board itself — the case has to come apart |
Texas Instruments Sitara AM335x. Two boards stacked, not one |
Xilinx and CVITEK are the pair that costs people boards. Both put a card slot on the front panel, both are a single PCB, and from the port edge there is nothing to choose between them — the processor marking is the only thing that separates them. Flashing a board with the other family's image is not a mistake another flash undoes; the board stops booting and stays that way. So the marking is worth reading twice before anyone writes anything to the card. If it is worn, scratched or hidden behind a heatsink bracket, photograph the chip and the port edge and send the pictures with your enquiry. We would rather identify the board for you than have you buy the wrong one.
Which miners take which board
The table below is assembled from the firmware builds that exist for each machine — a separate build has to be produced for every combination of miner and board family, so the set of builds is a statement about which combinations are real. Four things follow from it, and the first is the one that costs the most.
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The model on the sticker almost never decides the board. One and the same S19j Pro left the factory with all four families across different production runs.
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The exceptions worth naming. A plain S19, S19 Pro, T19 or L7 is always Xilinx. The S19 XP Hydro U3 is the one machine that has never turned up with anything but CVITEK. The S21 and the whole air-cooled S21 line are Amlogic.
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Families split at the execution, not at the model. The 88-chip S19 carries all four families; the 126-chip S19 carries only Amlogic and CVITEK. Same three characters on the sticker, different part in the chassis.
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No official list exists. Bitmain has never published a model-to-board table, and the lists kept by resellers disagree with each other at the edges.
| Miner |
Control board families it has shipped with |
| S19 |
Xilinx only |
| S19, 88-chip execution |
Xilinx, Amlogic, BeagleBone, CVITEK |
| S19, 126-chip execution |
Amlogic, CVITEK |
| S19+ |
Xilinx only |
| S19a |
Xilinx only |
| S19a Pro |
Xilinx only |
| S19i |
Xilinx only |
| S19j |
Xilinx, BeagleBone, CVITEK |
| S19j+ |
Xilinx, Amlogic, BeagleBone, CVITEK |
| S19j Pro |
Xilinx, Amlogic, BeagleBone, CVITEK |
| S19j Pro A |
Amlogic, BeagleBone, CVITEK |
| S19j Pro+ |
Xilinx, Amlogic, BeagleBone, CVITEK |
| S19j XP |
Xilinx, Amlogic, CVITEK |
| S19k Pro |
Xilinx, Amlogic, CVITEK |
| S19 Pro |
Xilinx only |
| S19 Pro A |
Xilinx only |
| S19 XP |
Xilinx, Amlogic, CVITEK |
| S19 XP+ |
Amlogic only |
| S19 Hydro |
Xilinx only |
| S19 Pro Hydro |
Xilinx only |
| S19 Pro Hydro 120T |
Xilinx only |
| S19 Pro+ Hydro |
Xilinx only |
| S19 XP Hydro |
Xilinx only |
| S19 XP Hydro U3 |
CVITEK only — the one machine with no other option |
| S19 XP+ Hydro |
Xilinx only |
| S19e XP Hydro |
Xilinx only |
| S21 |
Amlogic only |
| S21+ |
Amlogic only |
| S21 Pro |
Amlogic only |
| S21 Pro+ |
Amlogic only |
| S21 XP |
Amlogic only |
| S21 Immersion |
Amlogic only |
| S21 XP Immersion |
Amlogic only |
| S21 Hydro |
Xilinx only |
| S21+ Hydro |
Xilinx, CVITEK |
| S21 XP Hydro |
Xilinx only |
| S21e Hydro |
Xilinx, Amlogic |
| S21e XP Hydro |
Xilinx only |
| S21e XP Hydro U3 |
Xilinx only |
| T19 |
Xilinx only |
| T19 Hydro |
Xilinx only |
| T19 Pro Hydro |
Xilinx only |
| T21 |
Xilinx, Amlogic, CVITEK |
| L7 |
Xilinx only |
| L9 |
Amlogic, CVITEK |
A machine missing from this table is not a machine without a control board — it only means our build data does not reach it. Ask and we will tell you what we see on the bench. And where a row lists more than one family, the row is telling you that the model does not answer the question. Only the marking on the board does.
Control board replacement, by board family
Bricked after a firmware update?
A miner that stopped during or after an update is the one case nobody can settle by email, ourselves included. It may need its software restored and it may need a new board, and from where the owner is standing those two look identical: a machine with no lights, no address and no interface. Neither state tells you which it is. An interrupted write can leave the board perfectly recoverable, and it can also damage it past what any reflash reaches — and plenty of miners blamed on an update turn out to have had a hardware fault all along that the reboot simply exposed. Anyone who tells you which of those it is without seeing the machine is guessing. If it turns out the unit needs software rather than hardware, that work lives in our Antminer firmware section. If it needs a board, it needs a diagnosis first, and a diagnosis needs the machine on a bench.
Why replacement, not repair
Control boards are replaced rather than repaired, and the reason is arithmetic rather than skill. The processor alone, bought as a component, costs a large fraction of what a complete tested board costs, and getting it off and back on is BGA rework, not something an iron touches. So the bill for component-level work is bench hours and equipment, not parts — and at the end of it the customer owns a board with a reworked joint under load instead of a board that already works. Localised damage is the honest exception: a cracked Ethernet jack or a torn ribbon header is worth putting right, and we will say so when that is what we find. It is not what most dead boards have.
What sending the miner in involves
The work starts with a diagnosis, not with a part. A dead power supply and a failed hashboard produce the same outward picture as a dead control board, so the first job is proving which of the three actually failed — done by substitution on the bench, with a known-good board of the same family. What a diagnosis costs if you then decide not to go ahead, and who pays the return leg, are set out in our refund policy; we would rather point you at the terms than paraphrase them here.
Two things worth hearing before the machine ships. Your old board is disposed of — removed boards are not kept in storage, so if you want yours back, say so before the work starts. Expect the hashboards to need attention as well. In the machines that reach us a control board fault rarely arrives on its own, which is the real reason turnaround stays at 4-5 business days instead of being quoted as a same-day swap. One intake, one diagnosis, one shipment, rather than fitting a board and finding the actual problem afterwards.
All work is performed personally by Alex, who has been servicing ASIC miners since 2019. See credentials →
Send the whole miner rather than the board on its own — a board tested by itself carries no guarantee that it will work in your specific machine. Contact our repair team today and get your miner back to full power.
