Bitmain APW3++ Power Supply Unit Repair Guide & Components List

Bitmain APW3++ Power Supply Unit Repair Guide & Components List (2026 Update)

The Bitmain APW3++ is the legacy single-output PSU that powered the largest single fleet of ASIC miners ever shipped — the Antminer S9 series, plus L3+ / L3++ Scrypt miners and T9 / T9+ legacy SHA-256 units. Rated for 1600W at 220V AC input with a single 12V output at 133A, the APW3++ is built around a PFC-fronted LLC DC-DC half-bridge with secondary-side synchronous rectification. In 2026, with the Bitcoin network hashrate above 800 EH/s and difficulty above 110 trillion, many APW3++ units are still running 24/7 in low-cost-power environments and Bitcoin space-heater builds — bench repair is the only realistic path to keep these legacy PSUs alive. This guide covers the 19 most vulnerable components, the Bitmain-documented 5-stage diagnostic workflow, and the full repair playbook with direct sourcing links — completing our Bitmain APW PSU family coverage alongside the APW7 (S9 / L3 era), APW8 (S15 / T15), APW9 / APW9+ (S17), and APW12 (S19) repair guides.

Why APW3++ PSU Repair Still Matters in 2026

The APW3++ powered the largest installed base of Bitmain miners in history. Many S9 units remain in operation today in markets where electricity costs are low enough that the modest hashrate is still profitable, or as Bitcoin space heaters in Canadian, Northern European, and high-altitude installations where waste heat displaces conventional heating. Replacement APW3++ units have been out of Bitmain volume production for years; component-level repair is the only path to keep these PSUs alive. Most APW3++ failures trace back to aged primary MOSFETs, degraded electrolytic capacitors, a sacrificed varistor or NTC after a mains surge, or a worn fan that allowed thermal protection to start tripping — all replaceable parts with available repair stock.

Compatible Antminer Models

The APW3++ series powered the following Bitmain ASIC miners:

• S9 family: S9, S9i, S9j, S9k, S9 SE — the most widely deployed Bitmain miner ever produced (~14 TH/s class)
• L3 family: L3+, L3++ — Scrypt miners for Litecoin / Dogecoin mining
• Other legacy Antminer: T9, T9+, and select S7-era units that accept a 12V single-rail PSU

The APW3++ ships a single 12V DC output at 1600W via 10 PCIE 6-pin connectors. This single-rail architecture distinguishes it from the later APW8 / APW9 / APW9+ / APW12 family, which all carry a variable main rail plus a separate 12V auxiliary. The APW3++ is not directly interchangeable with newer PSU generations — the output topology, the connector format, and the voltage range are all PSU-generation-specific.

For the newer 1800W single-rail S9-class PSU, see our APW7 PSU repair guide. For the S15-class PSU with multi-rail output, see the APW8 article.

APW3++ PSU Architecture at a Glance

The APW3++ is a PFC-fronted LLC DC-DC half-bridge switching supply with secondary-side synchronous rectification, plus an internal standby supply for the primary and secondary control ICs and the fans. Bitmain's documented architecture is: AC input 176-264V → EMI filter (two common-mode chokes, two X-caps, six Y-caps, varistor) → bridge rectifier → PFC stage → VBUS bulk capacitor → LLC half-bridge → main transformer → secondary synchronous rectification → 12V DC output rated 133A. The standby supply branches off the primary side and provides VCC to the primary-side controller, the secondary-side controller, the protection circuits, the fans, and the input relay.

Specifications (APW3++)

• AC input: 176-264V universal, single-phase, C13 / C14 connector (100-240V auto-sensing with derating below 200V — full 1600W requires 220V input)
• DC output: 12V single rail at 1600W (full power on 200-240V input). Derated to ~1200W on 110V input.
• Output current: rated 133A continuous at 220V (100A continuous at 110V); OCP trips between 134-153A
• Voltage accuracy: <2% (acceptable range 11.6V to 12.6V under all conditions; nominal 12.15-12.25V at 1A no-load reference)
• Power factor: >0.99 at full load (220V input)
• Efficiency: >92% at full load (220V), ~93% peak
• Output ripple: <120mV at 133A full load
• Output cable: 10× PCIE 6-pin connectors (12-channel parallel output bus internally)
• Protection: under-voltage lockout, output short-circuit (locked, requires AC cycle), over-current locked, over-temperature with automatic recovery
• Operating temperature: 0°C to 40°C ambient (thermal shutdown above)
• Cooling: dual 40mm DC fans (intake + exhaust)
• Weight: approximately 3.0 kg

Component-level architecture

• EMI filter: two common-mode chokes, two X-capacitors, six Y-capacitors, and a S14K300 metal-oxide varistor (300VAC, 470V clamp, 4500A peak) clamps mains transients before they reach the bridge rectifier. F1 input fuse opens on hard primary faults. NTC 5D-15 thermistor limits inrush current at AC turn-on. HF115F-012 high-power DC relay bypasses the inrush thermistor once the bulk cap is charged.
• Bridge rectifier: GBJ2506 single-phase 25A / 600V bridge rectifier converts AC to pulsed DC at the PFC input.
• PFC stage: NCP1654BD65R2G (54B65) high-performance continuous-conduction-mode PFC controller drives the boost MOSFET to maintain unity power factor. IXFH46N65X2 high-voltage primary MOSFET (TO-247) handles the PFC boost switching. US1M ultra-fast recovery diode on the PFC boost output path. The PFC bulk capacitor (450V 470µF, 35×50mm) holds the bus voltage at 370-385V DC during normal operation (measured at TEST5/TEST6).
• Standby power: a small internal standby supply provides VCC to the primary-side controller, the secondary-side controller, the protection circuits, the relay coil, and the dual fans. If the standby fails, the PSU produces no response on AC power-on — fans don't spin and no 12V appears on the output.
• LLC DC-DC half-bridge: CM6901XISTR (CM6901X) resonant-mode controller drives the LLC half-bridge stage with combined LLC + secondary-synchronous-rectification control in a single IC. Light-load PWM function improves efficiency at low-hashrate states. ICE2QR4765 650V quasi-resonant offline AC/DC converter handles the primary quasi-resonant switching path.
• Gate drive: IX4424N (IX4424NTR) dual low-side MOSFET gate driver provides the high-current pulses needed to switch the primary MOSFETs cleanly under load.
• Synchronous rectification (output): secondary-side MOSFETs deliver the 12V output. AP431SAN1TR-G1 (GCC) shunt voltage regulator sets the output reference point and feeds the feedback loop.
• Output rectifier / freewheel: ES3J 600V super-fast recovery rectifier diode on the secondary path. B1100 100V Schottky diode handles low-loss low-voltage rectification on auxiliary rails.
• Output filtering: 1000µF 16V aluminum electrolytic capacitors on the secondary side hold the 12V rail steady. A 25V 220µF 8×12mm radial electrolytic supports auxiliary rail filtering.
• Feedback / sampling: TP2274-TR quad op-amp handles voltage sampling, error amplification, and feedback. The TP2274's high EMIRR (84dB at 900MHz) matters in the noisy switching environment a few centimetres from the LLC stage.
• Small-signal support: DSS5540X (-13) PNP BJT (40V / 4A, SOT-89) and MMBT3906 PNP transistor (SOT-23, 40V / 200mA) support the protection circuits and bias chains.
• Protection circuit ICs (Bitmain reference designators): U3 and U7 handle input protection; U10 paired with Q25 handles output current protection; U12 paired with Q30 handles over-temperature protection. Surrounding parts R34-R47, D13, D14, and C30-C40 form the protection support network.

Most Common APW3++ PSU Failure Modes

• Fans failing or noisy — usually the first APW3++ failure mode. The dual 40mm DC fans run continuously at high RPM in a hot, dusty environment. Grinding, rattling, or clicking sounds indicate bearing failure. PSU shutting down after 5-15 minutes of operation typically means one fan has failed and thermal protection is tripping. Spin each fan by hand with the PSU unplugged — any resistance or grinding means replacement.
• PSU dead after AC input, fan does not start — check the F1 fuse first. A blown fuse usually points to a downstream short on the primary switching stage (IXFH46N65X2 MOSFET or NCP1654 PFC controller). Also check the AC input cable and the C13 connector at the PSU inlet for damage.
• Fan spins but no 12V output, low mains voltage — the APW3++ requires AC input above 205V to enable the output. Low residential mains during peak hours can prevent the PSU from starting. Verify wall outlet voltage with a multimeter under load.
• Fan spins but no 12V output, output short or overload — the PSU latches into protection mode on output short or sustained overload. Disconnect the load, AC-cycle the PSU, and reconnect. If protection trips immediately, check the load (typically a miner hashboard short).
• Output voltage out of spec or drifting — degraded AP431SAN1TR shunt regulator drifts the reference. Inspect the TP2274-TR op-amp if the reference is healthy but output still drifts. Acceptable range is 11.6V to 12.6V; nominal target is 12.15-12.25V at 1A.
• AC ripple above 120mV — degraded output electrolytic capacitors. Hashboards are sensitive to voltage ripple; sustained out-of-spec ripple can kill ASIC chips. Replace the 1000µF 16V output capacitors if visible signs of swelling or leakage.
• Connector burnout — the 10× PCIE 6-pin connectors carry significant current (~15A per connector at full load). Poor contact creates resistance → heat → more resistance → thermal runaway. Discolored or melted plastic, blackened pins, or a burning smell are immediate-action conditions. Power off and inspect every connector on both PSU and miner side.
• PFC bus voltage missing — measure TEST5/TEST6 — should read 370-385V DC. If absent, check the 450V 470µF bulk capacitor, the IXFH46N65X2 MOSFET, the US1M boost diode, and the NCP1654 PFC controller in sequence.
• Repeated thermal shutdown — PSU shuts off after 10-30 minutes then restarts after cooling. First check fans (see above). Then check ambient temperature (rated 0-40°C) and PSU airflow — stacking PSUs, mounting against a wall, or placing in an enclosed shelf restricts airflow. Dust buildup on the heatsink fins reduces cooling efficiency even with healthy fans.
• Input protection device sacrificed — a mains surge can sacrifice the F1 input fuse and the S14K300 varistor together. Inspect both after any "PSU dead after thunderstorm" complaint. The varistor doing its job is a feature, not a failure — replace it and the fuse to restore input protection.

Bitmain APW3++ PSU Repair Components List

The table below lists every component LYS Shenzhen stocks for APW3++ PSU repair. Each entry links to the corresponding part page — contact us at contact@lys-sz.com for bulk pricing or for complete APW3++ PSU replacement units.

Diagnostic and Repair Workflow — 5-Step Bitmain-Documented Procedure

Bench setup requirements

• AC voltage regulator: auto-coupler 2000W, output 0-265V — required to verify the 205V startup threshold and to test universal-input behaviour.
• Electronic load tester: 1800W capable, 0-15V, 0-160A — required for the function test and OCP verification.
• Power analyzer: for power factor, real power, and efficiency measurement after repair.
• Multimeter: Fluke 15B+ recommended (capable of reading down to mV for ripple measurement on AC voltage mode).
• Oscilloscope: for inspecting the LLC switching waveform on the primary side and the synchronous rectification waveform on the secondary side when component-level diagnostics are unclear.
• Soldering equipment: 300W soldering iron, desoldering gun, anti-static brush, anti-static wrist strap, needle-nose pliers, tweezers, screwdriver, 150W protection lamp.
• Auxiliary materials: lead-free environmental-protection tin wire, washing water (flux remover), silica gel for protective glue replacement.

Safety — mandatory before opening the case

Power supplies store lethal amounts of energy even when unplugged. The bulk capacitors inside an APW3++ can hold a charge above 300V DC long after AC is removed. Always unplug the PSU and wait at least 60 seconds before opening the case. Wait for the fan to stop completely before touching the board — this confirms the bulk cap has discharged through the bleeder. Verify the residual voltage on the bulk cap with a multimeter — measure below 5V before you touch the board. Work on a grounded anti-static workbench, wear an anti-static wrist strap, and never bypass the F1 internal fuse with wire, foil, or a higher-rated fuse — the fuse is sized to protect the PSU and your home's wiring.

5-step diagnostic procedure

1. Step 1 — Visual inspection (PSU exterior + interior). Check the enclosure is not seriously damaged or deformed. Verify the AC inlet, the C13 socket, and the 10× PCIE 6-pin output connectors for damage, discoloration, melted plastic, or oxidised pins. After discharging the bulk cap below 5V, open the case (4 screws on the APW3++). Look for sparking marks, swollen or leaking capacitors, burnt traces, or components that have clearly overheated. A burnt-electronics smell when you open the case strongly indicates a component failure — the location of the strongest smell often points to the failed component.
2. Step 2 — Apply AC and verify basic operation. Connect AC input via the voltage regulator. Verify the fans rotate normally at the input. Use a multimeter on the output to confirm 12V is present. With electronic load set to 1A, record the output voltage — qualified range is 12.15-12.25V.
3. Step 3 — Verify startup threshold and load behaviour. Set the voltage regulator to 205V AC — the PSU should turn on. Below 205V the APW3++ correctly refuses to start (under-voltage lockout). With AC input at 220V and electronic load at 133A, record: output voltage stable, power factor >0.99, real power = 1600W, ripple <120mV (measure ripple in AC mV mode across the output). Efficiency at full load >92%.
4. Step 4 — Test overcurrent protection. Rotate the electronic load knob to increase current by 2A per step. The OCP should trigger between 134-153A. After OCP triggers, the PSU latches off until AC is cycled. Cycle AC and verify the PSU restarts normally — this confirms the latch-and-restart behaviour is healthy. Record the OCP trip value for the unit's QC log.
5. Step 5 — Verify internal protection chains. Power off, discharge bulk cap, open case. Measure: TEST5/TEST6 = 370-385V DC (PFC bus); TEST11/TEST6 = 11.5-13.8V (12V rail reference at the secondary side, no-load condition); TEST10/TEST9 = 11.5-13.8V (auxiliary rail reference). If any test point is out of spec, work back through the protection chain: input protection (U3, U7), current protection (U10 + Q25), temperature protection (U12 + Q30), and surrounding parts R34-R47, D13, D14, C30-C40.

Key test point voltages (Bitmain reference)

• TEST5/TEST6 (PFC bus, no load): 370-385V DC
• TEST11/TEST6 (output reference): 11.5-13.8V DC at no load
• TEST10/TEST9 (auxiliary rail reference): 11.5-13.8V DC at no load
• Output 12V rail at 1A load: 12.15-12.25V (qualified range)
• Output 12V rail under all conditions: 11.6-12.6V (acceptable range; outside indicates fault)
• Output AC ripple at 133A full load: <120mV (above indicates failing output capacitors)
• OCP trip threshold: 134-153A (locked, requires AC cycle to clear)
• AC input startup threshold: 205V (below this the PSU correctly refuses to start)

Common fault troubleshooting matrix (Bitmain reference)

Preventive Maintenance Schedule

Prevention beats troubleshooting. The APW3++ runs 24/7 in hot, dusty environments — a structured maintenance cadence catches degradation before it takes the miner offline.

When Chip-Level Repair Makes More Sense Than Replacement

New APW3++ PSU stock is constrained — Bitmain stopped volume manufacturing this generation years ago. For S9 / L3 / T9 fleet operators and Bitcoin space-heater builders, component-level repair is often the only realistic path. A small inventory of the IXFH46N65X2 primary MOSFET, the NCP1654 PFC controller, the CM6901X LLC controller, the ICE2QR4765 QR converter, the GBJ2506 bridge rectifier, the S14K300 varistor + matched F1 fuses, the NTC 5D-15 inrush thermistor, the HF115F-012 relay, the AP431SAN1TR shunt reference, the TP2274 op-amp, the output bulk caps (450V 470µF + 1000µF 16V), and the gate-drive parts (IX4424N, DSS5540X, MMBT3906) covers the vast majority of bench-repair scenarios. Many of these parts are shared with the APW7 and APW8 lines — a single repair stock covers APW3 / APW7 / APW8 / APW9 / APW12 across the older Bitmain PSU range.

Repair-vs-replace decision framework

Repair makes sense when: the issue is a failed fan (under $10 in parts, 15 minutes of work); a single connector needs re-termination; one or two components are visibly failed and the rest of the unit is in good condition; the operator has soldering skills and the right equipment.

Replace makes sense when: multiple electrolytic capacitors are bulging or leaking; the PCB has burn marks or damaged traces; the unit is more than 5-7 years of continuous 24/7 operation; repair cost would exceed 60% of a replacement PSU's value; or the operator is moving to a newer miner that needs a different PSU generation anyway.

FAQ — Bitmain APW3++ PSU Repair

Which Antminer models use the APW3++ PSU?

The APW3++ is the PSU for the Antminer S9 family (S9, S9i, S9j, S9k, S9 SE), the L3 family (L3+, L3++), and the T9 family (T9, T9+) plus select S7-era units. It delivers a single 12V rail at 1600W from a universal AC input (176-264V). Newer S15 / T15 miners use the APW8 (16-20V); S17-class miners use the APW9 / APW9+ (14.5-21V); S19-class miners use the APW12 (12-15V).

What topology does the APW3++ use?

The APW3++ is a PFC-fronted LLC DC-DC half-bridge switching supply with secondary-side synchronous rectification, plus an internal standby supply for the control ICs and fans. The PFC stage uses an NCP1654BD65R2G CCM controller with an IXFH46N65X2 boost MOSFET. The LLC stage is driven by a CM6901X LLC + SR resonant controller. The ICE2QR4765 handles a parallel quasi-resonant switching path. Output is a single 12V rail at 1600W via 10× PCIE 6-pin connectors.

What is the OCP (overcurrent protection) threshold on the APW3++?

The APW3++ rated output is 133A continuous at 220V input; the OCP triggers between 134A and 153A depending on production variant. After OCP triggers, the PSU latches off until AC power is cycled — at which point it should restart normally. Locked protection prevents the PSU from continuing to output into an abnormal load, a fire-safety design choice.

Why does the APW3++ deliver only 1200W on 110V input vs 1600W on 220V?

The APW3++ ships with universal 100-240V auto-sensing input but is derated on 110V mains. At 220V AC input, it delivers full 1600W rated power. At 110V AC input, it is limited to approximately 1200W. This is a physics constraint, not a defect — the input current rating limits the power transfer at low input voltage. For high-power S9 setups running near the PSU's full capacity, a 220V circuit is always the better choice for reliability and longevity.

How do I test the APW3++ after repair?

Bench test at 220V AC input with electronic load: at 1A load record 12.15-12.25V at the output; at 133A full load record voltage stable, PF >0.99, real power = 1600W, ripple <120mV. Then verify OCP triggers between 134-153A and that the PSU restarts after AC cycling. For full validation, follow with a soak test at 80% rated load (~106A) for a minimum of 2 hours before clearing the unit for customer use — this catches latent failures that survive the initial bench test but fail under sustained thermal stress.

My APW3++ is dead — should I repair or replace?

Quick rule of thumb: a single failed fan or a single damaged connector is always a repair (under $10 in parts). Multiple bulged capacitors, burn marks on the PCB, or a unit more than 5-7 years of 24/7 operation usually point to replacement. Contact LYS Shenzhen at contact@lys-sz.com for an assessment — we can ship replacement APW3++ units or the parts kit to repair the existing unit, whichever is more economical for your situation.

Sourcing APW3++ PSU Repair Parts

LYS Shenzhen stocks every component listed above for the Bitmain APW3++ PSU. For complete APW3++ PSU replacement units, for bulk farm-scale parts orders, or for the broader Antminer PSU lineup (APW7, APW8, APW9, APW9+, APW11, APW12, APW17), contact our team at contact@lys-sz.com — we operate an on-demand sourcing channel for repair components across the full Bitmain PSU generation range.

Worldwide shipping from our Shenzhen warehouse via DHL, FedEx, UPS, and sea freight. DDP shipping available for US and EU customers; case-by-case for other lanes — request a quote with your shipping country for confirmation.