​Welcome to Peak Asic's APW12 repair guide! We specialize in providing expert Antminer hashboard repairs, but we understand that some of you might want to try repairing your devices yourself. To support your efforts, we've created this comprehensive guide to help you through the process. Follow the steps below, and feel free to reach out to us if you need professional assistance or would like to send in miners for repair.

 I. Maintenance Platform Requirements

 1. Equipment:
- **Constant temperature soldering iron:** Above 80W, with a soldering temperature of 300-350℃ for small patches (resistors, capacitors) and 380-420℃ for plug-in components.
- **Heat gun:** For chip disassembly and soldering, set to 260℃ ±2℃. Avoid prolonged heating to prevent PCB blistering.
- **AC controllable power supply voltage regulator:** Output 200-250V, limit current 0-20A, used for APW12 power-on inspection. Alternatively, use a 100W light bulb connected to the AC live wire for safety.
- **Electronic load:** 3.6KW, suitable voltage 0-50V; if unavailable, create a power resistance load matching the APW12.
- **Multimeter:** Fluke 15b+ recommended.
- **Suction pistol, tweezers, hashboard testers:** ZJ0001000001 or V9 1.2, special power supply test card firmware. Use an oscilloscope if available.
- **Flux, lead-free solder wire, cleaning solution:** Use anhydrous alcohol for cleaning after maintenance.
- **Thermally conductive silicone grease (2500):** For heat conduction between MOS and heat sinks. Use 704 silicone to fix covers after repair.

 II. Maintenance Operation Requirements

 1. Personnel Expertise:
- Technicians must have electronic knowledge, over a year of maintenance experience, understand switching power supply principles, and master soldering techniques.

 2. Safety Precautions:
- Discharge large capacitors before opening the shell and repairing the PCBA board. Measure voltage with a multimeter and ensure it's less than 5V before performing welding operations to avoid electric shocks.

 3. Circuit Component Judgement:
- Replace components without deforming the PCB. Ensure reliable soldering and check for open or short circuits around the replaced parts.

 4. Post-Repair Checks:
- Verify that key components and the main circuit have no short circuits or obvious abnormalities before performing an AC voltage test to prevent explosion risks.

 5. Operational Safety:
- When handling AC220V voltage, use proper protection and follow safety guidelines.

 Additional Notes:
- Ensure maintenance personnel meet specified qualifications.
- Use appropriate instruments and equipment for repairs.
- Maintain anti-static environments and use anti-static wrist straps.
- Use production materials of corresponding models for repairs to ensure accuracy and traceability.

 General Guidelines:
- Only professionals should disassemble the shell to prevent electric shocks.
- Discharge high-voltage capacitors before starting repairs.
- Do not discard electronic waste improperly.
- Mark defective products and place them in designated areas.
- Systematically test repaired products before storage.

 III. Principle and Structure of Power Supply

 1. Principle Overview:
- **APW12 Composition:** Consists of a large board, three 60mm fans, and a lower shell. Connects to AC220V with two DC output voltages: SB, 12V, and an adjustable main voltage output (12V-15V) controlled by the PIC port and miner communication.

 2. Performance and Usage:
- **Voltage Output:** Adjustable 12V-15V, max current 12V/300A, 15V/240A. Fixed 12V output, max current 15A.
- **Features:** 
  - Wide voltage input (200-240V).
  - Internal protections: under-voltage, short-circuit, overload, over-temperature.
  - High-quality components for stability and reliability.
  - Small size and high power density.

 3. APW12 Appearance:
- **Front Panel:** 2 delta-shaped AC input ports, 3 medium-speed 60*60*25mm fans.
- **Left Side:** 2 copper solder terminals for adjustable voltage output, 1 4Pin signal terminal, 1 PCIE terminal for 12V fixed output.
- **Rear Panel:** Acts as the fan vent.

 4. Parameters:
- **APW12 Power Supply Parameter Table:** Provides detailed specifications.

 IV. Common Faults and Troubleshooting

 1. Fault Diagnosis:
- **Step-by-Step Process:** Inspect the power supply visually for damage, power on to check fan rotation, measure J6 terminal output voltage (12V), open the shell to check for sparking or scorching, and detect short circuits in AC input F1 fuse and other components.

 2. Power Supply PCB Layout:
- **Inspect Components:** Check for short circuits or open circuits in key components like the rectifier bridge, PFC MOS, PWM circuit MOS, and auxiliary 12V circuit components.

 3. Testing:
- **DC Output Test:** Short-circuit J15 PIN 4-5 pins and measure the main DC output voltage (about 21.3V).

 4. Maintenance and Repair:
- **Replace Damaged Components:** Ensure proper soldering and check surrounding circuits for damage. Verify power supply output and functionality before reassembling and performing AC220V tests.

 5. Control Board Testing:
- **V1.2 Control Board and APW9 Power PIC Port:** Use dedicated card test firmware, measure and adjust voltage, and ensure proper connections. After repairs, conduct a load test (12A under 12V, 170A under DC21V) to verify functionality.

 6. Post-Maintenance Testing:
- **Aging Test:** Operate the repaired power supply under an 80% (140A) rated load for 2 hours. If it passes, it's ready for customer use.

 7. Common Faults:
- **Fault Identification:** Simple judgment and maintenance of common faults, such as checking for short circuits, measuring voltage outputs, and verifying component functionality.

This guide ensures proper handling and repair of the APW12 PSU, emphasizing safety, accurate diagnostics, and thorough testing to ensure reliable repairs and customer satisfaction.