280W Power Supply Replacement for Dell Optiplex GX520 GX620 740 745

Our review of the 280W Power Supply Replacement for Dell Optiplex systems finds it best suited for users who need a direct, tested replacement for aging or failed OEM units. It delivers the core benefit of compatibility with a long list of Dell part numbers and desktop models, making it a straightforward swap for Optiplex GX520, GX620 and similar systems. The bottom line: buy this if you need a correct-fit power source that restores a working Dell desktop quickly and without fuss.

Key Features

• Wide compatibility: Supports many Dell part numbers such as MH596, MH595, RT490 and others so it replaces a range of original units without modification.
• Model match guidance: Lists compatible model numbers and prompts users to check their model number before purchase, which helps avoid ordering mistakes.
• Connector set: Supplies a 24-pin motherboard power, SATA and Molex connectors plus a floppy connector so typical Optiplex configurations are supported.
• Dual voltage input: Accepts 100-120V or 200-240V AC input (50-60Hz), enabling use in different regional mains without an external converter.
• Tested before shipping: Each unit is tested prior to dispatch, offering buyers reassurance that the power supply should power up on arrival.

Who It's For

This power supply is aimed at desktop owners, IT technicians and refurbishers who maintain Dell Optiplex GX520, GX620, 740, 745, 755 and a selection of Dimension and GX280 systems and need a direct, parts-compatible replacement. It is particularly useful for machines that require the specific 24-pin and legacy connectors listed.

It is less appropriate for users with modern small-form-factor desktops that use proprietary low-profile power supplies or for those who need higher wattage for power-hungry add-ons. Also check your exact part and model numbers before buying if your system is a close variant.

Pros & Cons

Pros

• Broad parts compatibility reduces time spent identifying the correct replacement.
• Complete connector set (24-pin, SATA, Molex, floppy) covers common drive and board needs.
• Dual voltage input makes it usable in different electrical regions without hardware changes.

Cons

• Limited to a 280W output, so it is not suited for heavily upgraded systems with modern high-draw components.

Specifications

Brand	Ratuforez
Output Power	280W Max
AC Input	100-120V~/6A, 200-240V~/3A (50-60Hz)
Connectors	1 x 24-pin MB, 2 x SATA, 1 x 4-pin Molex, 1 x Floppy, 1 x 4-pin ATX
Compatible Models	Optiplex GX520 GX620 740 745 755 210L 320 330; Dimension C521 3100; GX280 New Style
Compatible Part Numbers	MH596 MH595 RT490 NH429 P9550 U9087 X9072 NC912 JK930

Our Verdict

The 280W replacement is a pragmatic, cost-effective option for repairing legacy Dell Optiplex and compatible systems because it matches many OEM part numbers and provides the necessary connectors. It is good value for anyone restoring a standard office or home Dell desktop, but users with upgraded hardware should consider a higher wattage, modern supply.

Frequently Asked Questions

Will this fit my Optiplex GX520?
Yes, the unit lists Optiplex GX520 among compatible models, but you should confirm your original part number matches one of the listed part numbers before ordering.

Does it support both 120V and 240V?
Yes, it accepts 100-120V~/6A and 200-240V~/3A at 50-60Hz, so it can be used in different mains regions.

Are drives and peripherals supported?
Yes, the power supply includes SATA, 4-pin Molex and a floppy connector to support common drives and older peripherals.