1. Uvod
This manual provides comprehensive instructions for the installation, operation, and maintenance of the Dell 280W Power Supply Unit (PSU). This PSU is designed to deliver reliable and stable power to specific Dell desktop systems. Please read this manual thoroughly before proceeding with installation or maintenance to ensure proper and safe usage.

Slika 1: Prednja i bočna strana view of the Dell 280W Power Supply Unit.
2. Sigurnosne informacije
WARNING: Always disconnect the power cord from the wall outlet and the computer before servicing or installing any internal components. Failure to do so may result in electric shock, serious injury, or damage to the system.
- Do not attempt to open the power supply unit. There are no user-serviceable parts inside, and opening the unit may expose you to dangerous high voltages.
- Ensure proper grounding during installation to prevent electrostatic discharge (ESD) which can damage sensitive electronic components. Use an anti-static wrist strap if available.
- Keep the power supply away from moisture and extreme temperatures.
- Ensure adequate ventilation around the computer to prevent overheating of the power supply and other components.
3. Kompatibilnost
This Dell 280W Power Supply is specifically designed for compatibility with the following Dell Desktop Systems:
- Dell Optiplex Series: GX520, GX620, 740, 745, 755, 210L, 320, 330
- Dell Dimension Series: C521, 3100C
- New Style GX280 Systems
Compatible Dell Part Numbers (P/N): MH596, MH595, RT490, NH429, P9550, U9087, X9072, NC912, JK930
Compatible Dell Model Numbers: AA24100L, D280P-00, H280P-00, L280P-01, H280P-01, L280P-0, L220P-00, AA24120L, N220P-00, PS-5281-5DF-LF, H290E-00
4. Postavljanje i instalacija
Follow these steps carefully to install the Dell 280W Power Supply into your compatible Dell desktop system.
4.1 Potrebni alati:
- Phillips odvijač
- Anti-static wrist strap (recommended for ESD protection)
4.2 Koraci instalacije:
- Pripremite sistem:
- Shut down your computer completely and disconnect all cables from the computer (power, monitor, USB, etc.).
- Place the computer on a clean, flat, and static-free surface.
- Open the computer case according to your specific Dell system's service manual. Refer to Dell's official documentation for case opening procedures.
- Remove the Old Power Supply:
- Locate the existing power supply unit within the chassis.
- Disconnect all power cables from the motherboard, hard drives, optical drives, and any other components. Note the routing of these cables for easier re-installation.
- Unscrew the mounting screws that secure the power supply to the computer chassis.
- Carefully remove the old power supply from the case.
- Install the New Power Supply:
- Gently slide the new Dell 280W Power Supply into the designated bay.
- Align the screw holes and secure the power supply with the mounting screws. Do not overtighten.
- Connect the 24-pin motherboard power connector to the corresponding port on the motherboard.
- Connect the 4-pin ATX power connector (if applicable) to its designated port on the motherboard.
- Connect SATA power connectors to your hard drives and optical drives.
- Connect Molex and Floppy power connectors to any other required components.
- Ensure all connections are firm and correctly seated. Avoid forcing connectors.
- Zatvorite sistem:
- Carefully close the computer case, ensuring all panels are properly secured.
- Reconnect all external cables (power, monitor, keyboard, mouse, etc.) to the computer.
5. Uputstvo za upotrebu
After successful installation and reassembly of your system, press the power button on your computer. The power supply will automatically provide the necessary power to your system components. Observe the system's startup process and ensure all fans on the power supply and within the system are operating correctly. If the system does not power on, refer to the Troubleshooting section.
6. Održavanje
To ensure optimal performance, efficiency, and longevity of your Dell 280W Power Supply, periodic maintenance is recommended:
- Uklanjanje prašine: Every 6-12 months, with the system completely powered off and unplugged, use compressed air to gently clear dust from the power supply's fan and ventilation grilles. Accumulation of dust can hinder cooling, reduce efficiency, and potentially lead to overheating.
- Inspekcija kablova: Periodically inspect all power cables for any signs of wear, fraying, cuts, or damage. Replace damaged cables immediately to prevent electrical hazards or system malfunctions.
- Uslovi okoline: Ensure the computer is operated in a clean, dry, and well-ventilated environment. Avoid placing the computer in direct sunlight or near heat sources.
7. Otkrivanje problema
This section addresses common issues you might encounter with your power supply.
7.1 No Power / System Does Not Turn On:
- Provjerite priključke za napajanje: Ensure the main power cord is securely plugged into both the power supply and a working wall outlet. Verify all internal power connectors (24-pin, 4-pin ATX, SATA, Molex, Floppy) are firmly seated on the motherboard and components.
- Test Wall Outlet: Plug another known working device (e.g., a lamp) into the wall outlet to confirm it is receiving power.
- Verify Power Supply Switch: Some power supplies have an ON/OFF switch on the back panel. Ensure it is in the 'ON' (I) position.
- Isolate Components: Disconnect all non-essential components (e.g., extra hard drives, optical drives, expansion cards) and attempt to power on the system. If the system powers on, reconnect components one by one to identify a potentially faulty component drawing excessive power.
- Check Front Panel Connections: Ensure the power button cable from the front panel is correctly connected to the motherboard.
7.2 System Instability / Random Shutdowns:
- pregrijavanje: Ensure the power supply fan is spinning freely and not obstructed. Clean any dust buildup inside the power supply and computer case as described in the Maintenance section.
- Zahtjevi za napajanje: Confirm that your system's total power draw does not exceed the 280W capacity of the power supply. Adding new components (e.g., a more powerful graphics card) can increase power consumption beyond the PSU's capabilities.
- Labave veze: Recheck all power connections to the motherboard and components for secure seating.
- Faktori okoline: Ensure the computer is not in an excessively hot environment or has blocked ventilation.
8. Specifikacije
Detailed technical specifications for the Dell 280W Power Supply Unit.

Image 2: Specification label of the Dell 280W Power Supply, showing electrical ratings and model information.
| Feature | Detalj |
|---|---|
| Ulazni voltage | 100-120V~/6A or 200-240V~/3A |
| Ulazna frekvencija | 50-60 Hz |
| Izlazna snaga | 280W Max |
| +5V izlaz | 15A Max |
| -12V izlaz | 0.5A Max |
| +5V(FP) Output | 4A Max |
| +3.3V izlaz | 10A Max |
| +12V izlaz | 16A Max |
| Combined Power on +3.3V and +5V Rails | Not exceed 108W |
| Konektori | 1 x 24-pin Motherboard Power, 2 x SATA Power, 1 x 4-Pin Molex, 1 x Floppy Power, 1 x 4-Pin ATX Power |
| Dimenzije (približno) | 10.2 x 6.61 x 4.69 inča (pakovanje) |
| Težina (približno) | 3.54 funte |
| Compatible Part Numbers (P/N) | MH596, MH595, RT490, NH429, P9550, U9087, X9072, NC912, JK930 |
| Compatible Model Numbers | AA24100L, D280P-00, H280P-00, L280P-01, H280P-01, L280P-0, L220P-00, AA24120L, N220P-00, PS-5281-5DF-LF, H290E-00 |
| Manufacturing Identifiers | CN-0MH596-71615-81J-0028, REV A05 |
| UPC | 748926426664 |
9. Garancija i podrška
This Dell 280W Power Supply is provided as a Certified Refurbished product. This means it has undergone testing and certification to ensure it functions and appears like new. The refurbishing process includes comprehensive functionality testing, basic cleaning, thorough inspection, and professional repackaging.
The product includes a minimum 90-day warranty from the date of purchase. This warranty covers defects in materials and workmanship under normal use.
For technical assistance, warranty claims, or further support, please contact the seller from whom you purchased this product. Retain your proof of purchase for warranty validation.





