LAPTOP REPAIR GLOSSARY / PC HARDWARE / PSU

PSU (Power Supply Unit)

The component that converts mains AC power into the DC voltages your PC components need. Wattage, efficiency rating, and connector compatibility determine whether your PSU can support your build. A failing PSU is one of the most common causes of a desktop PC not turning on.

WHAT IT IS

The PSU (Power Supply Unit) is the component that sits inside your desktop PC tower and converts 240V AC mains power into the low-voltage DC rails that your components run on: +12V for the CPU and GPU, +5V and +3.3V for storage and motherboard logic.

Without a working PSU, nothing else in the system turns on. A dying PSU can also cause intermittent shutdowns, instability, and even damage to other components. Category: PC Hardware | Form Factor: ATX, SFX, TFX

HOW MUCH WATTAGE DO YOU NEED?

Build TypeGPURecommended PSU
Budget 1080p gamingRTX 3060550W 80+ Bronze
Mid-range 1440pRTX 3070 / 3070 Ti650W 80+ Bronze
High-end 4KRTX 3080 / 3080 Ti750W 80+ Gold
EnthusiastRTX 40901000W+ 80+ Gold

80+ EFFICIENCY RATINGS

80+ ratings indicate how efficiently the PSU converts AC to DC power at 20%, 50%, and 100% load. Higher efficiency = less heat generated and lower electricity bills.

80+ White — 80% efficient 80+ Bronze — 82–85% 80+ Silver — 85–88% 80+ Gold — 87–90% 80+ Platinum — 89–92% 80+ Titanium — 90–94%

SIGNS OF PSU FAILURE

PC won’t turn on at all — No fans, no lights, nothing. Dead PSU is the most common cause.
Random shutdowns under load — PSU can’t sustain the wattage demanded by the GPU during gaming.
System restarts without warning — Voltage drops trigger automatic restart protection. Can also cause BSODs.
Burning smell or coil whine — Electrical fault inside the PSU — stop using the PC immediately.

PEOPLE ALSO ASK

Can a bad PSU damage other components?

Yes — a failing PSU that delivers unstable voltages can damage the motherboard, GPU, and storage drives. Replace it promptly.

How long do PSUs last?

Quality PSUs from Corsair, Seasonic, or be quiet! typically last 5–10 years. Budget PSUs may fail sooner, especially under sustained high load.

Where can I get my PSU replaced in Singapore?

Bring your desktop to any of our 4 locations. PSU replacement starts from $80 including parts. See our desktop repair page.