1. Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of your Corsair HX850 80+ Platinum Certified Fully Modular Power Supply. The HX850 is designed for high-performance personal computers, offering exceptional voltage regulation, high efficiency, and quiet operation. Its 80 Plus Platinum certification ensures reduced operating costs and minimal heat generation, while the Zero RPM fan mode provides virtually silent performance under low to medium loads.
2. Safety Information
Please read and understand all safety warnings and instructions before installing or operating this product. Failure to do so may result in personal injury or damage to the product or other components.
- Electrical Hazard: Do not open the power supply unit. High voltages are present inside, even when disconnected from the AC outlet.
- Ventilation: Ensure adequate airflow around the power supply. Do not block any ventilation openings.
- Environment: Operate the power supply in a dry, well-ventilated environment. Avoid exposure to moisture, dust, and extreme temperatures.
- Grounding: Always connect the power supply to a grounded AC outlet using the provided power cord.
- Compatibility: Ensure the power supply's wattage and connectors are compatible with your system components.
3. Package Contents
Verify that all items listed below are included in your package:
- Corsair HX850 Power Supply Unit
- Modular Cable Set (including ATX 24-pin, EPS/ATX12V 4+4-pin, PCIe 6+2-pin, SATA, Peripheral 4-pin)
- AC Power Cord
- Cable Ties
- Mounting Screws
- User Manual (this document)
Image: Corsair HX850 Power Supply with its complete set of modular cables, ready for installation.
4. Setup and Installation
4.1. Pre-installation Checklist
- Ensure your computer is completely powered off and unplugged from the wall outlet.
- Discharge any static electricity by touching a grounded metal object before handling components.
- Gather necessary tools: Phillips head screwdriver.
4.2. Physical Installation
- Open your computer case.
- If replacing an existing power supply, disconnect all cables from the old PSU and remove it from the case.
- Carefully slide the Corsair HX850 into the power supply bay of your computer case.
- Secure the power supply to the case using the provided mounting screws. Ensure the fan is facing the correct direction for optimal airflow (typically facing down if your case has a bottom vent, or up if it's a top-mounted PSU).
Image: The Corsair HX850 Power Supply, showing its compact form factor and fan grill, ready for installation.
4.3. Cable Connections
The HX850 is a fully modular power supply, allowing you to connect only the cables necessary for your system, which improves cable management and airflow.
- 24-pin ATX Cable: Connect the large 24-pin cable from the PSU to the corresponding port on your motherboard.
- EPS/ATX12V (CPU) Cable: Connect the 4+4-pin or 8-pin CPU power cable(s) to the CPU power connector(s) on your motherboard.
- PCIe (GPU) Cables: Connect the 6+2-pin PCIe cables to your graphics card(s). Use separate cables for each PCIe power input on your GPU for optimal stability, especially with high-power graphics cards.
- SATA Cables: Connect SATA power cables to your SSDs, HDDs, and optical drives.
- Peripheral (Molex) Cables: Connect peripheral 4-pin cables to any components requiring Molex power (e.g., older fans, fan controllers).
- Ensure all connections are secure and properly seated. Route cables neatly to improve airflow and aesthetics.
Image: Close-up view of the Corsair HX850's modular connection panel, showing clearly labeled ports for various cables including 24-pin ATX, PCIe, CPU, and SATA/Peripheral.
5. Operating Instructions
5.1. Zero RPM Fan Mode
The Corsair HX850 features a Zero RPM fan mode. This means the power supply fan will not spin when the power supply is under low to medium loads. This results in virtually silent operation. The fan will automatically activate and spin up as the load on the power supply increases to maintain optimal cooling.
5.2. +12V Rail Switch
The HX850 includes a switch to select between a single +12V rail or multiple +12V rails. This switch is located on the modular connection panel. For most modern systems and ease of use, the 'Single' +12V rail setting is recommended. The 'Multiple' +12V rail setting provides individual overcurrent protection for each +12V output, which can be beneficial in specific scenarios or for troubleshooting.
Image: Top-down view of the Corsair HX850, highlighting the large, quiet fan that operates in Zero RPM mode under low loads.
6. Maintenance
Proper maintenance ensures the longevity and optimal performance of your power supply.
- Cleaning: Periodically clean the exterior of the power supply and its fan grill to prevent dust buildup. Use compressed air to gently clear dust from inside the unit's vents. Ensure the power supply is unplugged before cleaning.
- Environment: Maintain a clean and dust-free computing environment.
- Cable Management: Ensure cables are not obstructing airflow within the case.
7. Troubleshooting
If you encounter issues with your Corsair HX850 power supply, refer to the table below for common problems and their solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| System does not power on. | Power cord not connected, PSU switch off, loose internal connections, faulty component. | Check power cord connection to wall and PSU. Ensure PSU switch is ON. Re-seat all modular cables. Test with minimal components. |
| System powers on but no display. | Loose GPU power cable, faulty GPU, RAM issues. | Ensure PCIe power cables are fully seated. Test GPU in another slot or system if possible. Check RAM seating. |
| Power supply fan not spinning. | Zero RPM mode active, low system load. | This is normal under low loads due to Zero RPM mode. The fan will spin up under higher loads. If fan never spins under heavy load, contact support. |
| System crashes or reboots randomly. | Insufficient power, unstable power delivery, overheating. | Ensure total system wattage is within PSU capacity. Check all cable connections. Monitor system temperatures. |
8. Specifications
| Feature | Detail |
|---|---|
| Brand | Corsair |
| Model Name | HX850 80+ Platinum Fully Modular |
| Item Model Number | CP-9020138-NA |
| Output Wattage | 850 Watts |
| Efficiency Certification | 80 Plus Platinum |
| Form Factor | ATX |
| Cooling Method | Air (135mm FDB fan with Zero RPM mode) |
| Dimensions (L x W x H) | 15 x 18 x 8.6 Centimetres (approx. 14.99 x 18.03 x 8.61 cm) |
| Item Weight | 1.95 kg (4.29 Pounds) |
| Connector Type | ATX (Fully Modular) |
| Compatible Devices | Personal Computer |
9. Warranty and Support
The Corsair HX850 Power Supply is backed by a 10-year warranty, demonstrating Corsair's commitment to quality and reliability. This warranty covers defects in materials and workmanship under normal use.
For technical support, warranty claims, or further assistance, please visit the official Corsair support website or contact their customer service department. Keep your proof of purchase for warranty validation.