Computer power supplies

Computer power supply prices

Manly Electronics maintains the following power supplies for repairs and computer assembly.

Cooler Master PSUs

PSU	power	price
	420 watts	$40
	500 watt	$70
	750 watt	$130

Power supply failures

PC Power Supply Unit issues can produce the symptoms listed below.

• Failure to turn on
• Brief startup followed by automatic shutdown
• Starting up to the login screen and then shutting down
• Normal startup followed by shutdown after a period of use
• Freezing or being stuck on the Windows icon
• Slow or unresponsive operation
• Intermittent blue screens
• Shutdown under heavy load such as gaming
• Random restarts or shutdowns
• Unusual noises or signs of burning
• Components not functioning correctly (USB ports, graphics card, hard drive)

These symptoms may indicate PSU faults or other hardware and software issues. A complete diagnostic check isolates the cause and determines whether replacement is required. Calculate required PSU capacity if you built your own PC by using the PSU power calculation method.

Power Supply Selection and Troubleshooting

Choosing power adapters for laptops and Mac

Mac laptops and other notebooks follow strict power requirements. Use a higher wattage Mac power supply in place of a lower wattage one, but avoid lower wattage replacements. Match voltage exactly on any laptop PSU and allow higher current in amps where required. Do not use a higher voltage unit, as this can damage the device.

Power Supply Failure: A Case Study in PC Gaming

A PC with an 850 watt power supply and a ROG Strix GeForce GTX 1080Ti experienced shutdowns during PUBG. The system operated normally with another graphics card. Driver changes, clean booting, and removing additional software did not resolve the fault. Replacing the PSU with a 650 watt unit restored stable gaming at half the cost of the original power supply.

Calculating PSU power

The PSU powers all components in a computer. Determine required wattage by adding the Thermal Design Power (TDP) values of each component.

Power consumption range for components in a consumer PC

PSU for office PCs

CPU and GPU determine most of the power requirement. With CPU TDP between 50W and 80W, GPU between 50W and 250W, and roughly 100W for the motherboard and storage, a 500W PSU meets the needs of most office and mid-range gaming systems.

PSU for gaming

High-end gaming systems require substantially more power. A configuration with an RTX 4090 at 450W TDP and an Intel i9-12900 at 125W TDP, plus high-end supporting components, pushes the requirement above 700W. Systems with multiple GPUs may need over 1000W. Add a 20 to 30 percent overhead to accommodate load spikes and future upgrades.

Other PSU requirements

Evaluate additional specifications when selecting a PSU.

Efficiency: Efficiency describes how much incoming power is converted for component use rather than lost as heat.

Rails: Some PSUs divide output across multiple rails. Single rail or multi-rail units are suitable for general use.

Modularity: Modular units reduce cable clutter. Non-modular units offer fixed cables. Semi-modular units provide a mix of both.

Connections: Confirm that the PSU includes the required connectors. Use fewer adapters to reduce potential failure points.

Size: Match the PSU form factor to the case, especially in compact builds.

Warranty: Longer warranties and reputable brands support long-term reliability.

The PSU directly affects system stability. Select a reliable unit to avoid preventable failures and protect components.

Installing an Uninterruptible Power Supply

An uninterruptible power supply (UPS) protects equipment from voltage spikes and provides temporary backup power during outages. Many UPS models can shut down computers automatically when unattended. A 500W UPS starting at $100 typically supports an office computer for a short outage.

Contact Computer Repairs in Sydney to install or advise on the correct UPS and PSU setup for your system.