Antminer S19 Maintenance & Repair Guide

Introduction

The Bitmain Antminer S19 is the machine that restored confidence in Bitmain’s engineering after the troubled S17 generation. Released in mid-2020, the S19 brought 95 TH/s of SHA-256 hashrate at roughly 34.5 J/TH efficiency — a massive leap that made the S17 look like a prototype. More importantly, it delivered something the 17-series desperately lacked: reliability. Where S17 units earned a reputation for hashboard connector failures, heatsink delamination, and chronic overheating, the S19 simply runs. And runs. And keeps running.

At the heart of the S19 sits the BM1398 ASIC chip — Bitmain’s 7nm workhorse that packs 76 chips across each of its four hashboards. That is right: four hashboards, not three. The S19 broke from the three-board convention that defined every Antminer from the S9 through the S17. This four-board architecture distributes heat and power more evenly, contributing directly to the platform’s legendary uptime. The BM1398 chip operates at a remarkably low ~0.36V per chip, organized into 38 voltage domains of two chips each — a design that balances efficiency against fault tolerance.

The S19 became one of the most widely deployed Bitcoin miners in history. You will find them in institutional data centers, home mining setups, repurposed as Bitcoin Space Heaters, and humming away in basements from Montreal to Mumbai. The massive installed base means that maintaining, diagnosing, and repairing these machines is a skill that pays for itself many times over. Every S19 you keep hashing is another decentralized node defending the Bitcoin network — and that matters more than any efficiency spec on a datasheet.

This guide is your complete field manual. We cover routine maintenance that prevents problems before they start, diagnostic procedures that identify problems when they appear, and repair techniques that fix problems when they strike. Whether you are running a single S19 as a dual-purpose heater-miner in your Canadian home or managing a rack of them in a dedicated facility, this guide gives you the knowledge to maintain your hardware like a professional technician.

Technical Specifications

Before you pick up a screwdriver or plug in a multimeter, know your hardware. The S19 is a significant architectural evolution from the S17 — different chip, different board count, different power delivery, different thermal design. If you are coming from S9 or S17 repair experience, do not assume old procedures transfer directly. The four-hashboard layout changes everything from airflow dynamics to diagnostic workflows.

S19 Series Variants

The S19 is the base model in a large and successful family. While this guide focuses on the standard S19, the maintenance principles apply broadly across the lineup:

All air-cooled S19 variants share the same basic architecture: four BM1398-based hashboards, APW12 family PSU, and the same control board platform. Chip counts and frequencies vary between models. Hydro variants use a completely different cooling system and are outside the scope of this air-cooled maintenance guide.

Understanding the Hashboard Architecture

Each S19 hashboard contains 76 BM1398 ASIC chips arranged in 38 groups (domains), with 2 chips per group. The operating voltage per chip is ~0.36V. Understanding the signal and power architecture is essential for advanced diagnostics:

• Power delivery: The APW12 supplies 14V to each hashboard. A boost circuit on each board steps this up to 19V for the LDO power rails. Groups 32 through 38 (7 groups) receive 1.8V power from LDOs fed by this 19V boost output. Groups 1 through 30 are supplied by VDD at 13.64V through individual LDOs, with domain voltage stepping down 0.36V per group.
• CLK (XIN) signal: Generated by the Y1 25MHz crystal oscillator, transmitted from chip 01 through chip 76. Normal voltage: 0.7V–1.3V.
• TX (CI/CO) signal: Enters from the control board IO connector pin 7 at 3.3V, passes through level conversion (U2), then transmits from chip 01 to chip 76. Standby: 0V; computing: 1.8V.
• RX (RI/RO) signal: Returns from chip 76 to chip 01, exits through U1 back to the control board via pin 8. Standby: 0.3V; computing: 1.8V.
• BO (BI/BO) signal: Transmitted from chip 01 to chip 76. Multimeter reading: 0V.
• RST signal: Enters from IO connector pin 3, transmitted from chip 01 to chip 76. Standby: 0V; computing: 1.8V.

Understanding these signal paths is critical for fault localization. When a chip fails or a solder joint cracks, the signal chain breaks — and knowing the direction of signal flow tells you exactly where to look.

Before You Begin

Safety Warnings

Summary of safety rules:

1. Power off and unplug before any maintenance. Wait 5 minutes for capacitor discharge.
2. Wear an ESD wrist strap grounded to the miner chassis whenever handling hashboards.
3. Let the miner cool for 10+ minutes after shutdown before touching heatsinks.
4. Work in a clean, dry environment — no liquids near the miner, no metal shavings, no conductive debris.
5. Never operate the miner with the cover removed — airflow direction is critical for proper cooling across all four hashboards.
6. Follow the power connection sequence — negative first on, last off. Signal cable last on, first off.
7. Document everything — photograph cable positions and connector orientations before disconnecting anything.
8. Keep a Class C fire extinguisher within arm’s reach when testing powered equipment.

Routine Maintenance

Prevention is cheaper than repair — every time. A disciplined maintenance schedule extends the life of your S19, maintains peak hashrate, and prevents the catastrophic failures that turn a profitable miner into scrap metal. The BM1398 chips are engineered for years of continuous operation, but only if you give them clean air, proper cooling, and stable power. The S19 is far more reliable than the S17 generation, but “more reliable” is not “maintenance-free.”

Recommended Maintenance Schedule

Visual Inspection

Start every maintenance session with a visual and auditory check. You are looking for the early warning signs of problems that become expensive if ignored:

• Dust accumulation — The S19 moves a massive volume of air through four hashboards. Dust accumulates on fan blades, heatsink fins, and the intake grill. Heavy dust buildup restricts airflow, raises chip temperatures, triggers thermal throttling, and forces fans to spin faster (louder, shorter lifespan). In dusty environments — garages, basements with exposed concrete, pet-heavy homes — double your cleaning frequency.
• Fan noise — All four fans should produce a consistent, smooth hum. Grinding, clicking, or rattling indicates worn bearings. Fan bearing wear is one of the most common S19 failure modes over time. Replace a noisy fan before it seizes — a seized fan causes immediate thermal throttling and can lead to chip damage within minutes.
• Discoloration on hashboards — Brown or yellow discoloration around components indicates overheating. This is a red flag that demands immediate investigation. Check for blocked airflow, failed fans, or degraded thermal paste.
• Connector condition — Inspect the power connectors between the APW12 PSU and each hashboard. Look for green or white oxidation, discoloration, or melting. Connector oxidation is a common S19 issue in humid environments and causes voltage drops, increased resistance, and eventually connector failure.
• Flat ribbon cables — Check the data cables connecting each hashboard to the control board. These are fragile. A cable that has been pinched, bent sharply, or pulled at an angle can cause intermittent hashboard detection failures. If a hashboard appears and disappears from the dashboard, suspect the ribbon cable first.
• Physical damage — Bent heatsink fins, cracked PCB traces, loose screws, damaged fan blades. Shipping damage is common with S19 units — always inspect a new or used unit before first power-on.

Cleaning Protocol

Dust is the number one enemy of any air-cooled ASIC miner. Establish a cleaning schedule based on your environment:

Cleaning procedure:

1. Power down: Shut down the miner via the web interface (System > Reboot), then disconnect the APW12 from the wall. Wait 5 minutes for capacitors to discharge.
2. Disconnect cables: Unplug all power cables from the hashboards and control board. Unplug the fan connectors and Ethernet cable. Take a photo first if you are not familiar with the layout.
3. Remove fans: Unscrew the Phillips screws holding each fan assembly. Set fans aside. The S19 has four fans — label or photograph their positions if they are not interchangeable in your unit.
4. Compressed air — hashboards: Hold the air can upright (tilting releases liquid propellant that damages components). Blow air in the same direction as normal airflow (front to back) across each of the four hashboards. Focus on the heatsink fins — dust packs tightly between the aluminum fins. Use short, controlled bursts.
5. Compressed air — fans: Hold each fan blade to prevent spinning while cleaning. Spinning a fan with compressed air generates back-EMF that can damage the motor or control board connector. Clean both sides of each fan.
6. Clean the control board: Gently brush the control board with an anti-static brush. Blow remaining dust with compressed air. Pay attention to the Ethernet port, flat ribbon cable connectors, and fan headers.
7. Inspect connectors: While everything is disassembled, inspect all power connectors for oxidation or heat damage. Clean any visible corrosion with IPA and a lint-free cloth.
8. Reassemble: Reinstall fans, reconnect all cables (check your photos for correct orientation), reconnect Ethernet, and finally reconnect the APW12 to wall power.

Thermal Paste Replacement

Thermal paste degrades over time. After 12–18 months of continuous operation, the thermal interface material between the BM1398 chips and their heatsinks begins to dry out, crack, and lose thermal conductivity. The symptom is gradually increasing chip temperatures at the same ambient temperature and fan speed — a slow death spiral that eventually triggers thermal throttling and hashrate loss.

Signs thermal paste needs replacement:

• Chip temperatures have crept up 5–10°C over several months with no change in ambient conditions
• Temperature spread between hottest and coolest chips has increased significantly
• Thermal throttling occurs at ambient temperatures that previously caused no issues
• Visual inspection shows dried, cracked, or chalky thermal paste

Thermal paste replacement procedure:

1. Power down, unplug, and wait for full cool-down (minimum 15 minutes).
2. Remove the top cover and disconnect the hashboard you are servicing.
3. Carefully remove the heatsink by unscrewing the mounting hardware. Note the screw pattern — some heatsinks use a specific tightening sequence.
4. Clean the old thermal paste from both the chip surfaces and the heatsink contact surfaces using 99% IPA and lint-free cloths. Be thorough. Any residual old paste creates air pockets that act as thermal insulators.
5. Apply fresh thermal paste evenly across each chip surface. Use a thin, uniform layer — more is not better. You want complete coverage without excess that can squeeze onto surrounding components.
6. Reinstall the heatsink with even pressure. Tighten screws in a cross pattern (like tightening wheel lug nuts) to ensure even contact pressure across all chips.
7. Repeat for each hashboard that needs service.

Fan Maintenance

The S19 uses four high-speed fans — two intake, two exhaust. These fans are the miner’s respiratory system. When they degrade, everything else suffers.

Fan bearing wear is the most common mechanical failure point on the S19. Symptoms progress in a predictable pattern:

1. Stage 1: Occasional clicking or ticking at low RPM (especially at startup). May be intermittent.
2. Stage 2: Consistent grinding or rattling noise during operation. Fan RPM may fluctuate.
3. Stage 3: RPM drops below the dashboard’s minimum threshold. The miner reports a fan error and may shut down.
4. Stage 4: Fan seizes completely. Without replacement, chip temperatures spike and the miner enters thermal protection within minutes.

Do not wait for Stage 3 or 4. Replace fans at Stage 2. A seized fan during unattended operation can cause chip thermal damage that costs far more than a replacement fan.

Fan replacement procedure:

1. Power down, unplug, and wait for cool-down.
2. Disconnect the fan connector from the control board (4-pin header). Note which header it connects to.
3. Unscrew the fan assembly mounting screws (usually 4 Phillips screws per fan).
4. Remove the failed fan and install the replacement. Ensure the airflow direction arrow on the fan matches the original orientation (intake fans blow in, exhaust fans blow out).
5. Reconnect the fan connector to the correct header on the control board.
6. Power on and verify via the web dashboard that the replacement fan is reporting normal RPM.

Diagnostics & Troubleshooting

When your S19 is not performing as expected, systematic diagnostics beat guesswork every time. The web dashboard, SSH access, and a multimeter are your primary diagnostic instruments. This section walks through the most common diagnostic scenarios and how to interpret what you find.

Web Dashboard Diagnostics

The miner’s web interface (accessible via its IP address in a browser) is your first stop for diagnostics. The dashboard should show:

• 4 hashboard chains — each reporting their full chip count (76 chips per chain for the standard S19)
• 4 fan RPM readings — all within normal operating range
• Chip temperatures — ideally 55°C–75°C, never above 90°C
• Hashrate — stable around ~95 TH/s (5-minute average)
• Pool connectivity — active connection to your configured mining pool

Any deviation from these baselines is a diagnostic lead. Missing chains, reduced chip counts, elevated temperatures, and fluctuating hashrate all tell a story.

SSH Diagnostic Commands

For deeper diagnostics, SSH into the miner’s Linux-based control board. The default credentials on stock Bitmain firmware are typically root / root (change this immediately if you have not already).

ssh root@MINER_IP_ADDRESS

# View real-time mining log output
tail -f /var/log/miner.log

# Check for error messages in the log
grep -i "error|fail|warn" /var/log/miner.log | tail -50

# Check kernel messages for hardware issues
dmesg | tail -100

# Check system uptime (how long since last reboot/crash)
uptime

# Check miner process status
ps | grep -i "cgminer|bmminer"

# View chip temperature readings
cat /tmp/temp_sensor.log 2>/dev/null || echo "Check web dashboard for temps"

# Check network connectivity to pool
ping -c 4 stratum.pool-address.com

# View hashboard detection status
cat /tmp/miner_status.log 2>/dev/null

The miner log is your gold mine for diagnostics. Key patterns to search for:

• Chain [X]: find 0 chips — Hashboard X is not being detected at all. Could be a dead board, bad ribbon cable, or power delivery failure.
• Chain [X]: find N chips (where N < 76) — Hashboard X has missing chips. Indicates chip failure, signal chain break, or solder joint issue.
• NONCE error — Chips are computing but returning incorrect results. Usually indicates chip damage or thermal stress.
• fan lost or fan speed abnormal — Fan failure detected. Miner will throttle or shut down for thermal protection.
• temp too high — Chip temperature exceeded the safe threshold. Miner enters protective shutdown.
• power supply failure — APW12 PSU not delivering expected voltage.

LED Status Indicators

The control board LEDs provide quick visual diagnostics without needing network access:

Common Diagnostic Scenarios

Scenario 1: One Hashboard Not Detected (3 of 4 Chains Visible)

This is one of the most common S19 issues. The dashboard shows only 3 chains instead of 4, and hashrate is down ~25%.

Diagnostic steps:

1. Reseat the ribbon cable — Power off, unplug, and carefully disconnect and reconnect the flat ribbon cable between the missing hashboard and the control board. This alone fixes the problem in about 30% of cases.
2. Swap ribbon cables — If reseating does not work, swap the ribbon cable from the missing board with one from a working board. If the problem follows the cable, replace the cable. If the problem stays with the board slot, continue diagnostics.
3. Check power delivery — Measure the voltage at the hashboard’s power connector. You should see approximately 14V from the APW12. No voltage means a PSU power rail issue or damaged connector.
4. Check the boost circuit — With power applied to the hashboard (via test fixture), measure the boost circuit output at C55. You should read ~19V. If not, the boost converter circuit has failed.
5. Check the PIC circuit — Measure U3 pin 2. You should see ~3.3V. If absent, the PIC may need reprogramming or the tester cable connection is faulty.
6. Test the hashboard on a fixture — If you have an ARC Kit or Bitmain test jig, test the board independently. This isolates whether the issue is the hashboard itself or the control board slot.

Scenario 2: Incomplete Chip Count on a Hashboard

A hashboard is detected but reports fewer than 76 chips. For example, 75/76, 70/76, or anything less than the full count.

Diagnostic steps:

1. Check the miner log — The log will indicate which specific ASIC numbers are missing. This tells you exactly which chips in the signal chain are affected.
2. Measure domain voltages — Each domain should show approximately ~0.36V. Walk through the domains with a multimeter. An abnormal voltage (significantly higher or lower than 0.36V) indicates the problem domain.
3. Check the LDO outputs — Measure 1.8V (VDD1V8) and 0.8V (PLL 0V8) at the test points near each chip group. Abnormal voltages here indicate an LDO failure or a chip pulling the rail down.
4. Check signal continuity — The CLK, CI, RI, BO, and RST signals flow from chip 01 to chip 76 (except RX, which flows in reverse). A break in the signal chain at chip N means chip N or the component between chip N-1 and N has failed.
5. Use the short-circuit method — Short the 1V8 test point and the RO test point between chips to progressively narrow down the location of the faulty chip. This is the most reliable localization technique for S19 hashboards.

Scenario 3: Hashrate Fluctuation and Gradual Decline

All four boards are detected with full chip counts, but hashrate is unstable or slowly declining.

Diagnostic steps:

1. Check temperatures — Rising chip temperatures (especially if ambient temperature has not changed) point to thermal paste degradation, dust buildup, or fan degradation.
2. Check fan RPMs — All four fans should be running at similar speeds. One slow fan can create a thermal imbalance across the hashboards.
3. Reduce frequency — If available in firmware, try reducing the mining frequency slightly. If hashrate stabilizes at a lower frequency, you likely have a marginal chip that cannot sustain full-speed operation. This is often caused by thermal paste degradation allowing the chip to run hotter than optimal.
4. Check for NONCE errors in logs — Excessive NONCE errors indicate chips returning bad results. Identify which chip has the lowest response rate — this chip is likely damaged or has a poor solder joint.
5. Monitor over time — Track hashrate, temperature, and fan speed over 24–48 hours. Some issues only manifest under sustained thermal load.

Scenario 4: Miner Cannot Find IP / No Network

The miner powers on, fans spin, but you cannot find it on your network or access the web interface.

Diagnostic steps:

1. Check the Ethernet cable — Replace with a known-good cable. A damaged RJ45 connector is surprisingly common.
2. Check the Ethernet port LEDs — Link/activity LEDs on the RJ45 jack should light up when connected to a live network port.
3. Use Bitmain’s IP Reporter — Press the IP Reporter button on the control board. Use Bitmain’s IP Scanner tool on a PC connected to the same network to listen for the broadcast.
4. Try a direct connection — Connect the miner directly to your PC with an Ethernet cable (you may need a crossover cable or a switch between them). Set your PC to a static IP in the 192.168.x.x range and try to access the miner at its default IP.
5. Check the control board — If no network activity at all, the control board may have failed. Try a known-good control board if available.

Common Repairs

This section covers the most frequent repairs D-Central performs on S19 units. Some of these are straightforward enough for a well-equipped home miner. Others require professional soldering skills and specialized test equipment. We will be honest about which is which — attempting a chip-level repair without proper equipment risks turning a fixable problem into a dead hashboard.

Fan Replacement

Difficulty: Beginner   |   Time: 10–15 minutes per fan

Fan replacement is the most common S19 repair and the easiest. Fan bearing wear is inevitable over time — the S19’s high-speed fans run continuously at thousands of RPM, and bearings simply have a finite lifespan. In our experience, most S19 fans last 18–30 months of continuous operation before bearing wear becomes noticeable.

Procedure:

1. Power down, unplug, wait for cool-down.
2. Disconnect the fan’s 4-pin connector from the control board.
3. Remove the 4 mounting screws on the fan assembly.
4. Install the replacement fan, matching the airflow direction to the original (check the arrow on the fan frame).
5. Reconnect the 4-pin connector.
6. Power on and verify RPM on the dashboard.

Power Supply (APW12) Issues

Difficulty: Beginner to Intermediate   |   Time: 15–30 minutes

The APW12 PSU is generally reliable, but it is still the single point of failure that powers the entire miner. Common symptoms of PSU problems:

• Miner does not power on at all — no fan spin, no LEDs. Check the wall outlet, the power cable, and the APW12’s indicator LED. If the APW12 LED is off, the PSU may have failed internally. Try a different power cable first.
• Miner powers on but hashboards show voltage errors — The APW12 may be delivering voltage outside the acceptable range. Measure the output voltage at the hashboard power connectors. You should see approximately 14V. Voltage significantly below or above this range indicates PSU regulation failure.
• Miner reboots intermittently — Could indicate the PSU is unable to sustain peak load. This can happen with aging PSUs whose capacitors have degraded, or when the AC input voltage is too low (the APW12 requires 200–240V and does NOT support 120V).

Hashboard Repairs

Difficulty: Intermediate to Advanced   |   Time: 30 minutes to several hours

Hashboard repair is where the real diagnostic skill comes in. The S19’s four hashboards are complex multi-layer PCBs with 76 BM1398 chips each, surrounded by hundreds of passive components (resistors, capacitors, LDOs, MOSFETs). Common hashboard failure modes include:

Chip Failure (ASIC Reports 0 or Missing Chips)

A failed BM1398 chip breaks the signal chain. The hashboard tester or miner firmware reports 0 chips detected (complete signal chain failure) or a reduced chip count (partial chain break).

Repair procedure (requires test fixture and soldering equipment):

1. Routine visual inspection: Check the hashboard for obvious deformations, scorching, burnt marks, offset components, or missing parts.
2. Impedance testing: Measure the impedance of each voltage domain to detect short circuits or open circuits before applying power.
3. Power on test fixture: Following the correct power sequence (negative first, then positive, then signal cable), connect the hashboard to the test fixture.
4. Locate the faulty chip: Using the domain voltage measurements and signal flow analysis (CLK, CI, RI, BO, RST), identify the domain where the signal chain breaks. Short the 1V8 and RO test points progressively to narrow down the exact chip.
5. Rework the chip: First attempt to reflow the suspected chip by applying flux around it and heating the solder joints to reflow temperature. This resolves cold solder joint issues without chip replacement.
6. Replace the chip: If reflowing does not fix the issue, remove the failed chip using a hot air rework station. Pre-tin the new BM1398 chip’s pads with solder paste, then solder it to the PCB. Apply thermal paste evenly on the chip surface and reinstall the heatsink.
7. Post-repair testing: The repaired hashboard must pass the test fixture at least twice, with a cool-down period between tests, before being considered a good repair.

Boost Circuit Failure

Each hashboard has a boost converter that steps up the PSU’s 14V input to 19V for the LDO power rails. If the boost circuit fails, the entire hashboard goes dark.

Diagnosis: Measure the voltage at capacitor C55 on the hashboard. Expected reading: ~19V. If absent or significantly off, the boost circuit components (typically the converter IC U9, inductor, or associated MOSFETs) need inspection and likely replacement.

MOSFET Short Circuits

Failed MOSFETs are a common cause of domain voltage anomalies. A shorted MOSFET can prevent power from reaching an entire voltage domain.

Diagnosis: Measure the resistance between MOSFET pins 1, 4, and 8. A dead short (near 0 ohms) indicates the MOSFET has failed and needs replacement.

Temperature Sensor Issues

The S19 uses four temperature sensors per hashboard (U4, U6, U7, U8) located on the back of the PCB, with their associated resistors on the front. If the test fixture displays “PIC sensor NG” or reports abnormal temperatures:

1. Check resistors R24–R27 for solder joint integrity.
2. Check the welding quality of U3 pins 2 and 3.
3. Check all four temperature sensor circuits: U4 (R28, R30), U6 (R31, R33), U7 (R34, R36), U8 (R37, R39).
4. Verify the 3.3V power supply to the temperature sensors is present and stable.
5. Inspect the solder joints between the thermal sensor chip pads and their associated small heatsinks.

Control Board Issues

Difficulty: Intermediate   |   Time: 15–30 minutes (replacement) / Variable (diagnosis)

Control board failures are less common than hashboard issues but do occur. Symptoms include:

• Miner boots but does not detect any hashboards
• Network interface dead (no link LEDs, miner not discoverable)
• All hashboards show errors despite testing good individually on a fixture
• Firmware corruption (boot loop, stuck at Bitmain splash screen)

Control board replacement is straightforward: power off, disconnect all cables (ribbon cables, fan headers, Ethernet, power), remove mounting screws, install the replacement, and reconnect everything. The control board stores mining pool configuration — you will need to reconfigure pools after replacement.

Firmware recovery: If the control board has corrupted firmware but is otherwise functional, you can often recover it by flashing firmware via a microSD card. Download the appropriate firmware version from Bitmain’s support page, write it to a FAT32-formatted microSD card, insert it into the control board’s card slot, and power on. The miner will automatically flash from the card.

Connector Oxidation Repair

Difficulty: Beginner   |   Time: 20–40 minutes

Connector oxidation is a slow-burning problem that gets worse if ignored. In humid environments (coastal regions, unsealed basements, poorly ventilated spaces), the power connectors between the APW12 and the hashboards develop a layer of copper oxide that increases resistance. Increased resistance means voltage drops under load, which causes the hashboard to behave erratically — intermittent chip detection failures, fluctuating hashrate, and in severe cases, connector overheating and melting.

Prevention and repair:

1. During quarterly maintenance, inspect all power connectors for green or white residue.
2. Clean oxidized connectors with 99% IPA and a small brush. For heavy oxidation, use a fiberglass pen (electronics grade) to gently abrade the contact surfaces.
3. Apply a thin layer of dielectric grease (DeoxIT or similar) to connector pins after cleaning. This prevents future oxidation while maintaining electrical contact.
4. If a connector shows signs of heat damage (discoloration, melting, deformation), replace the connector entirely. Do not attempt to reuse a heat-damaged connector — the resistance has already increased permanently.

Firmware & Software

The S19 runs Linux-based firmware on its control board. Keeping firmware current and properly configured is essential for stability, performance, and security.

Firmware Updates

Bitmain periodically releases firmware updates that fix bugs, improve performance, and sometimes add features. To check your current firmware version, log into the web interface and look under System > Version or System > About.

Firmware update procedure:

1. Download the correct firmware from Bitmain’s support page. Verify you are downloading for the exact S19 model (S19, S19 Pro, S19j, etc. — firmware is NOT interchangeable between variants).
2. Log into the miner’s web interface.
3. Navigate to System > Firmware Upgrade.
4. Select the downloaded firmware file and click Upgrade.
5. Wait for the process to complete. Do not power off the miner during a firmware upgrade — this can brick the control board.
6. The miner will reboot automatically after the upgrade. Verify the new version in the web interface.

Aftermarket Firmware Options

The S19 supports aftermarket firmware such as Braiins OS+ (formerly known as BOS+). Aftermarket firmware can offer benefits including:

• Autotuning — automatically adjusts chip frequency and voltage per-chip to optimize performance. This can improve efficiency by 5–15% depending on your specific hardware’s silicon quality.
• Better monitoring — more detailed per-chip data, temperature history, and error logging.
• Power capping — set a maximum watt draw and let the firmware optimize hashrate within that envelope. Excellent for home miners on limited circuits.
• Pool fee considerations — some aftermarket firmware charges a devfee. Evaluate whether the efficiency gains exceed the fee.

Research thoroughly before switching firmware. Aftermarket firmware may void Bitmain’s warranty (if any remains), and switching firmware incorrectly can require control board recovery. Always back up your current firmware and pool configuration before switching.

Configuration Best Practices

• Configure backup pools: Set up at least two backup pool addresses. If your primary pool goes down, the miner automatically switches to the backup instead of sitting idle.
• Change default passwords: Change both the web interface password and the SSH root password immediately after first setup. Default credentials are widely known.
• Set a static IP: For stable monitoring and management, assign a static IP to your miner instead of relying on DHCP. This prevents IP changes after power outages or router reboots.
• Configure time (NTP): Ensure the miner’s clock is synchronized via NTP. Incorrect time can cause pool authentication failures.
• Monitor with external tools: Consider using monitoring tools like Foreman, Awesome Miner, or Hive OS (with compatible firmware) to track fleet performance over time and receive alerts when metrics drift.

Advanced Repair Reference

This section provides reference information for technicians performing board-level repairs. If you do not have soldering equipment, a test fixture, and at least one year of electronics repair experience, this section is informational — not a DIY invitation. Improperly performed chip-level repairs will make the problem worse.

Repair Workstation Requirements

A proper S19 repair workstation includes:

• Anti-static workbench — Grounded surface with ESD mat and wrist strap connection point.
• Constant temperature soldering iron (350°C–380°C) with fine-point tip — For soldering small SMD components (0402 resistors, capacitors).
• Hot air rework station / BGA rework station — For BM1398 chip removal and installation.
• Digital multimeter — Fluke 15b+ recommended. Weld steel pins to the probes and apply heat-shrink sleeves for precise measurements on densely-packed hashboards.
• Oscilloscope — UTD2102CEX+ or equivalent. Required for signal analysis (CLK, TX, RX signal integrity).
• Hashboard test fixture — ARC Kit (with Lab PSU 10–30V / 1–15A) or Bitmain kit (APW12 AP12_12V-15V_V1.2 with adapter cable and V2.3 control board test fixture).
• Consumables: Solder paste (138°C), flux, lead-free circuit board cleaner, anhydrous alcohol, thermally conductive gel, ball-planting steel mesh, desoldering wick, 0.4mm solder balls.
• Spare components: 0402 resistors (0R, 10K, 4.7K), 0402 capacitors (0.1uF, 1uF), replacement BM1398 chips.

Hashboard Repair Sequence

The S19 hashboard repair flow follows a strict sequence. Skipping steps leads to misdiagnosis:

1. Visual inspection — Check for deformation, scorching, offset or missing components. Use magnification. Many faults are visible before you power anything on.
2. Impedance testing — Measure each voltage domain impedance to check for short circuits or open circuits. This step prevents powering on a shorted board that could damage your test fixture.
3. Domain voltage measurement — With power applied, verify each domain reads approximately ~0.36V. Deviant domains indicate the fault location.
4. Boost circuit verification — Confirm 19V output at C55.
5. PIC circuit verification — Confirm 3.3V at U3 pin 2.
6. Signal chain analysis — Measure CLK, CI, RI, BO, RST signals at each chip. Compare readings against the known-good voltage ranges to identify the break point.
7. Chip test (PT1) — Run the test fixture’s chip detection test. Note the exact chip count and any specific ASIC numbers reported as missing or faulty.
8. Functional test (PT2) — Run the full pattern/nonce test. Note response rates per chip. Identify chips with abnormally low nonce response rates.
9. Targeted repair — Rework or replace the identified component.
10. Post-repair verification — The repaired board must pass testing at least twice, with a complete cool-down between tests. If the test fails immediately, stop and re-diagnose. If it fails after running for a while, there may be a thermal-related issue (poor heatsink contact, degraded thermal paste).

The S19 as a Bitcoin Space Heater

The Antminer S19 draws approximately 3250W from the wall and converts virtually all of that energy into heat. That makes it roughly equivalent to three residential space heaters — except it also mines Bitcoin while heating your space. For Canadian home miners especially, dual-purpose mining makes perfect economic sense: you are paying for heating anyway, so you might as well stack sats while staying warm.

D-Central Technologies has been building and selling Bitcoin Space Heaters since long before it became trendy. Our Space Heater editions integrate ASIC miners with custom enclosures and ducting that direct hot exhaust air into living spaces efficiently and (relatively) quietly.

Key considerations for S19 space heater use:

• Noise: The S19 at stock settings is loud — roughly 75 dB. This is not livable for most people without sound dampening. Consider aftermarket firmware with fan control, or a custom enclosure with sound insulation and duct routing to move the miner to a less noise-sensitive location.
• Airflow routing: Use ducting to direct the hot exhaust air where you want it. The S19’s exhaust is concentrated and directional — perfect for duct integration.
• Summer operation: Unless you want supplemental heating year-round, you need a plan for summer. Some operators duct exhaust outdoors in warm months. Others reduce mining frequency to lower heat output. Others simply power down and buy their sats on an exchange until fall.
• Electrical requirements: A single S19 requires a dedicated 240V circuit. Running it alongside other major appliances on the same circuit will trip breakers.

When to Call a Professional

There is no shame in calling for backup. ASIC repair is a specialized skill that requires expensive equipment and hard-won experience. Here is our honest assessment of what to DIY and what to send to a professional:

D-Central Technologies offers professional ASIC repair services from our facility in Laval, Quebec. We have been repairing Antminers since 2016, with over 2,500 miners serviced. The S19 is our most commonly repaired current-generation machine — we know every failure mode, every component, every signal path on these boards.

Frequently Asked Questions

Keep Your S19 Hashing

The Antminer S19 is one of the most successful Bitcoin miners ever built — a machine that brought 7nm efficiency to the masses and proved that Bitmain could deliver reliability after the S17 generation’s stumbles. With proper maintenance, your S19 will mine profitably for years. With neglect, it becomes an expensive dust collector.

The maintenance playbook is simple: keep it clean, keep it cool, keep the firmware current, and catch problems early. Weekly dashboard checks catch issues before they cascade. Monthly cleaning prevents the thermal problems that kill chips. Annual thermal paste replacement keeps efficiency at peak levels. And when something does break — because eventually, something always does — the diagnostic procedures in this guide help you identify the problem quickly and decide whether it is a DIY fix or a professional repair.

Every Antminer S19 that keeps hashing is another contribution to Bitcoin’s decentralized security. Every home miner who learns to maintain their own equipment is one step closer to the sovereign, decentralized mining ecosystem that Bitcoin was designed to support. You do not need permission to participate in securing the most important monetary network in human history. You just need to keep your hardware running.

D-Central Technologies is here when you need us. We stock S19 replacement parts, we repair hashboards and control boards at our facility in Laval, Quebec, and we are a phone call away at 1-855-753-9997. We are Canada’s Bitcoin Mining Hackers, and we have been keeping miners hashing since 2016.

Mine on.

Interactive Hashboard Schematic

Explore the ANTMINER S19 hashboard layout below. Toggle layers to isolate voltage domains, signal chains, test points, key components, and thermal zones. Hover over any region for quick specs — click for detailed diagnostics, failure modes, and repair guidance.