The Power Supply: The Most Overlooked Component
The **power supply unit (PSU)** converts mains power into the stable voltages your computer's components need. It is not glamorous, but it is arguably the most critical component in a desktop PC — a failing PSU can damage every other part it powers.
Despite this, PSUs are rarely the first thing people check when a computer starts misbehaving.
Warning Signs of a Failing Power Supply
1. Random Shutdowns or Restarts
If your computer shuts down or restarts unexpectedly — particularly under load (gaming, video rendering, or opening multiple programs) — a PSU struggling to deliver stable power under demand is a common cause.
2. The Computer Will Not Turn On at All
A completely dead computer — where pressing the power button produces nothing — can indicate a failed PSU, especially if the power light on the motherboard is also off. However, check the obvious first: the power cable, power point, and surge protector.
3. Blue Screen Errors With Power-Related Codes
BSOD errors such as **KERNEL_POWER_ERROR** or **WHEA_UNCORRECTABLE_ERROR** can indicate PSU instability, particularly if they occur under load.
4. System Instability Under Load
If your computer runs stably at idle but crashes during demanding tasks, this points to a PSU that cannot sustain its rated wattage. This is especially common with older PSUs and systems where the GPU or CPU has been upgraded without upgrading the PSU.
5. Unusual Sounds From the Power Supply
A grinding, clicking, or high-pitched coil whine from the area of the power supply (typically in the top or bottom rear of the case) indicates mechanical issues with the PSU fan or electrical instability.
6. Burning Smell
Any burning smell from your computer should prompt an immediate shutdown. A burning smell from the PSU area is serious — continuing to run the computer risks fire or damage to other components.
Diagnosing a Failing PSU
Diagnosing a PSU definitively requires a multimeter or a specialised PSU tester to measure actual output voltages under load. This is not something to attempt without experience.
An easier diagnostic approach is process of elimination — swapping in a known-good PSU of appropriate wattage and testing stability.
Professional Diagnosis and Repair in Midland
Midland Computers provides expert [desktop PC hardware diagnosis and repair in Midland](/services/computer-repairs-midland). Our technicians can quickly identify whether your PSU, motherboard, or another component is responsible for your system instability.
We stock a range of quality power supplies for desktop PCs and can replace a failing unit promptly. We also carry out [data recovery](/services/data-recovery) in cases where a failed PSU has damaged storage.
Do not ignore the warning signs — a failing PSU that goes unaddressed often takes other components with it when it fully fails. [Book a diagnostic](/book-repair) or [contact our team](/contact) today.