If your PC makes a sharp clicking or ticking sound from the power supply area and then instantly shuts off, you are hearing a protection circuit trip. The click is usually a relay or the over-current / short-circuit protection engaging, followed by the PSU cutting power to prevent damage. The system may try to restart on its own, fail to POST, or stay off until you flip the switch on the back of the PSU or unplug it for a few seconds. In some cases you will also see the case or PSU fan twitch once and stop.
This is an urgent issue. Repeated protection trips mean the PSU is detecting a fault that could damage your motherboard, GPU, or storage if you keep forcing it on. Do not continue to power cycle the PC dozens of times to get it to boot. Work through the ordered fixes below from easiest to most invasive. As of 2026, most modern ATX 3.0 and ATX 3.1 units have stricter transient load protection, so even a loose cable or a brief short can cause this exact clicking and shutdown behavior.
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Likely Causes
| Cause | How to confirm | Fix difficulty |
|---|---|---|
| Loose or improperly seated power cables (24-pin, EPS 8-pin, PCIe 12VHPWR / 12V-2×6) | Wiggle test: shutdown correlates with case movement; visual check shows cable not fully latched until you hear a click | Easy |
| Overload, power strip failure, or wall voltage sag | PC runs fine when plugged directly into a known-good wall outlet; other devices on same strip also flicker or reset | Easy |
| Short circuit from case contact, loose screw, or pinched cable | System only clicks when motherboard tray or GPU bracket is flexed; shutdown started after new build or hardware change | Moderate |
| Dust, debris, or failing PSU fan causing over-temperature protection (OTP) | PSU exhaust feels very hot before shutdown; fan does not spin or makes grinding noise; shutdown takes longer under load | Moderate |
| Failing component drawing excessive current (GPU, drive, or peripheral short) | Disconnecting a specific GPU, SATA drive, or USB device stops the clicking; HWInfo or BIOS shows 12V rail dropping under load | Moderate |
| Internal PSU failure (capacitor, relay, or protections degraded) | Clicking and shutdown occurs even with minimal load outside the case using paperclip test; paper smell or rattling inside PSU | Hard / Replace |
Fix 1: Reseat All Power Cables and Check the Latches
What causes it
A partially seated ATX 24-pin, EPS 12V 4+4-pin, or PCIe power cable creates intermittent contact and high resistance. Modern PSUs interpret the resulting voltage drop and current spike as a short and trigger SCP/OCP with an audible relay click.
How to check
Power off completely. Flip the PSU rocker switch to O, unplug the wall cord, then press and hold the front case power button for 10 seconds to drain residual power. Remove the side panel and inspect the 24-pin motherboard connector on the right edge of the board, the 8-pin EPS connector at the top-left near the CPU, and the PCIe cables at the GPU. If the clip on the connector is not fully over the tab on the socket, or you can see any gold pins, it is not seated.
What to do
Disconnect and reconnect each power cable one at a time until you hear and feel a positive latch click. For the 24-pin, support the back of the motherboard with your other hand while pressing firmly. For 12VHPWR or 12V-2×6, push straight in without an angle until the connector is flush with the GPU socket and the sense pins are fully engaged. Ensure the PSU-side modular cables are in the correct labeled ports: CPU/EPS is not PCIe, even if the pin shape looks similar. Route cables so they are not pulling at an angle or pinched behind the motherboard tray.
How to undo it
No undo is needed. If the reseat made boot issues worse, recheck that you did not swap a CPU cable with a PCIe cable at the PSU modular panel and that no pin was bent during reconnection.
Fix 2: Eliminate the Outlet, Power Strip, and Cable as the Source
What causes it
A failing surge protector, overloaded power strip, underrated extension cord, or loose wall outlet can sag under load. The PSU detects input under-voltage and shuts down to protect itself, often with a click just before power loss.
How to check
Note whether the clicking only happens when the PC, monitor, and other peripherals are on the same strip, or when a heater, air conditioner, or vacuum runs on the same circuit. Check if the power strip LED flickers or the strip feels warm.
What to do
Plug the PSU power cord directly into a known-good wall outlet, bypassing any strip, UPS, or extension cord. Use the thick 18AWG or 16AWG cord that came with the PSU, not a thin spare from a monitor. Flip the PSU switch to I and try to boot. If you must use a strip, use a single 15A-rated strip with built-in breaker and do not daisy-chain strips. In Windows, open Event Viewer via Windows key + X > Event Viewer > Windows Logs > System and look for Kernel-Power Event ID 41 entries clustered around your shutdown times to confirm input power loss rather than a software crash.
How to undo it
Reconnect your original strip and peripherals if direct wall power made no difference. If direct wall power fixed it, replace the strip.
Fix 3: Clear Dust and Verify PSU and Case Airflow
What causes it
Choked intake or a stalled PSU fan causes internal temperature to rise until over-temperature protection trips. The PSU will click off under gaming load but may idle fine for a while.
How to check
With the PC off and unplugged, shine a flashlight into the PSU intake grill (usually bottom of the case) and the rear exhaust. Look for a mat of dust on the fan blades or filter. Power on briefly and check if the PSU fan spins at all during startup. Most PSUs spin for 1-2 seconds at power-on even in zero-RPM mode.
What to do
Remove the PSU filter and wash it with water, dry completely, then reinstall. Use short bursts of compressed air to clear the PSU from the outside only. Hold the fan blade with a finger so it does not overspin. Do not open the PSU housing. Ensure the PSU intake has at least 1 inch of clearance if bottom-mounted and that the case intake and exhaust fans are set to a normal curve in BIOS: restart and press Delete or F2 during POST > Hardware Monitor or Fan Control > set CPU and System Fans to Standard or Normal, not Silent, and confirm they report RPM values. Keep the PC on a hard surface, not carpet.
How to undo it
Return fan curves to your previous profile in BIOS > Hardware Monitor if noise is an issue. Reinstall any dust filter you removed.
Fix 4: Check for a Short From Loose Hardware or Pinched Wires
What causes it
A loose motherboard standoff screw trapped under the board, a frayed front-panel cable, or a pinched SATA power wire touching the case can create a direct short to ground. The PSU instantly clicks and shuts down on power-on.
How to check
With power fully disconnected, gently rock the case and listen for a screw rattling. Inspect the motherboard mounting points: every standoff should align with a board hole, with no extra standoff under the board where there is no hole. Look for pinched cables between the side panel and motherboard tray, especially the 24-pin bundle and front panel connectors at the bottom-right of the board (labeled JFP1, F_PANEL).
What to do
Remove any extra standoffs and retrieve loose screws with tweezers. Reroute any cable that is crimped or has exposed copper, and replace it if the insulation is cut. Disconnect front panel USB and audio headers temporarily to test: unplug the USB 3.0 header (wide blue connector, usually labeled USB3_1) and the HD Audio header (labeled JAUD1 or AAFP) from the motherboard, then try to boot using only the front power button pins. If the system stays on, one of those front I/O cables is shorted.
How to undo it
Reconnect front panel USB and audio headers one at a time to isolate the faulty cable, then leave the faulty cable disconnected until replaced.
Fix 5: Isolate a Failing GPU, Drive, or USB Device
What causes it
A GPU with a failing VRM, a SATA SSD/HDD with a shorted 5V rail, or a damaged USB device can pull the 12V or 5V rail out of spec, triggering OCP. The click happens the moment that device is initialized.
How to check
Boot with minimal hardware. Power off, unplug, then disconnect all SATA power cables from drives, all USB devices except keyboard and mouse, and any PCIe cards except the GPU. If you have integrated graphics, try removing the discrete GPU entirely and plugging the monitor into the motherboard HDMI or DisplayPort. Check BIOS hardware monitor: restart > Delete / F2 > Hardware Monitor or HW Monitor > Voltages. Look for 12V, 5V, and 3.3V readings that are more than 5 percent away from nominal while idle.
What to do
Reconnect devices one by one, powering off at the PSU switch between each addition. First add the boot drive, then the second drive, then USB devices. If you have a second PCIe power cable, try a different modular port on the PSU and a different cable. If the system only clicks when the dedicated GPU is installed, test the GPU in a different PCIe x16 slot or in another PC if available. In Windows, you can also check Device Manager via Windows key + X > Device Manager > Universal Serial Bus controllers for devices reporting Device Descriptor Request Failed, which can indicate a shorted USB peripheral.
How to undo it
Reinstall all hardware you removed. If a specific drive or peripheral caused the shutdown, leave it disconnected and back up its data from another system before replacing it.
Fix 6: Reset BIOS Power Settings and Disable Aggressive Protections Misconfiguration
What causes it
Incorrect BIOS power limits or ERP settings can conflict with PSU protections, especially after a BIOS update or after enabling extreme overclocking. High transient loads from CPU boost can trip an undersized or older PSU.
How to check
Enter BIOS: restart and repeatedly tap Delete or F2 until BIOS appears. Look under Overclocking, OC, or Tweaker > CPU Power Management or CPU Voltages, and under Settings > Advanced > Power Management Setup. Note if CPU Power Limits are set to Unlimited, or if ERP Ready, Deep Sleep, or Power Loading is enabled.
What to do
Load optimized defaults: in BIOS, press F6 or select Load Optimized Defaults, then Save and Exit. For a more targeted reset, set CPU Long Duration Power Limit (PL1) and Short Duration Power Limit (PL2) back to Auto instead of manual high values, and set CPU Core Voltage to Auto. Disable any manual overclock and set XMP/EXPO back to Disabled temporarily for testing. In Windows, reset power plan: Control Panel > Hardware and Sound > Power Options > Balanced > Change plan settings > Change advanced power settings > PCI Express > Link State Power Management > set to Maximum power savings, then test. Also run a clean driver check if shutdowns correlate with GPU load spikes: use Display Driver Uninstaller is not required; instead set Windows > Settings > System > Display > Graphics > change from High performance if you forced it.
How to undo it
Re-enable XMP/EXPO in BIOS > Overclocking > A-XMP or DRAM Profile and reapply your stable CPU overclock. Return Power Options > PCI Express > Link State Power Management to its previous value.
Fix 7: Test the PSU Outside the Case and Inspect for Internal Failure
What causes it
Internal component degradation, a stuck relay, or dried capacitors will cause clicking even with no real short. This often shows as random shutdowns at idle as well as under load.
How to check
Perform a minimal bench test. Power off, unplug, and remove the PSU or leave it mounted but disconnect every cable from the motherboard, GPU, and drives. Perform the paperclip test only if your PSU manual allows it: unplug the 24-pin from the board, bend a paperclip to short the green-adjacent PS_ON pin (pin 16, green wire side) to any black ground pin, then plug the PSU into the wall and flip the switch. If the PSU fan twitches and clicks off with nothing connected, the unit itself is faulty. Also sniff the rear exhaust for a burnt or sweet chemical odor and listen for loose debris when gently tilting the unit.
What to do
Do not open the PSU housing. Capacitors inside can hold lethal charge even when unplugged. If the bench test fails or you see bloated vent caps through the grill, stop using the PSU and replace it. Choose a replacement with appropriate wattage for your GPU and CPU combined plus 30 percent headroom, ATX 3.1 support if you use a 40-series or 50-series GPU, and the correct native 12V-2×6 cable if required. Keep the replacement’s modular cables with that unit only; never mix modular cables between PSU brands.
How to undo it
Reconnect all original cables if the PSU passed the bench test and the clicking stopped, which points back to a case short or component issue from Fixes 4 and 5. If you replaced the PSU, retain the old unit for warranty RMA but do not reinstall it.
If Nothing Works
If the clicking and shutdown persists after reseating cables, testing on wall power, clearing dust, checking for shorts, and isolating components, the PSU is likely failing its own self-tests. At this point, avoid repeated forced boots. Reassemble the system to a minimal boot configuration: motherboard, one RAM stick in slot DIMM_A2, CPU and cooler, and integrated graphics if available, with no drives or extra fans on the same SATA chain. If it still clicks off, you have confirmed the fault is the PSU or motherboard VRM, not a peripheral. Replace the PSU first, as it is the cheaper and more common culprit, and test again before replacing the motherboard. Save your BIOS settings by noting them or taking photos before swapping hardware, and keep all modular cables bundled with their original PSU for warranty return. If the system is under warranty, contact the PSU manufacturer with your model, serial on the PSU label, purchase date, and a short video of the click and shutdown behavior to start an RMA.
FAQ
Is a clicking PSU dangerous and should I keep using my PC?
Stop using it for gaming or work until diagnosed. Each click is a protection trip, and continued trips can degrade the PSU and stress the motherboard and GPU. It is safe to perform the brief checks above, but do not run extended stress tests or games while it is shutting off.
Why does my PC click and shut off only when I launch a game?
Games create sudden transient power spikes from the GPU and CPU. If the PSU is undersized, has a weak 12V rail, or the PCIe cable is not fully seated, the spike exceeds the over-current limit for a few milliseconds and the PSU trips. Reseating cables and testing on a direct wall outlet fixes many load-specific cases; if not, a higher-wattage ATX 3.1 unit with native 12V-2×6 support is usually required.
Can a faulty RAM stick or CPU cause the PSU to click?
Rarely. RAM and CPU faults usually cause blue screens or no POST without a PSU relay click. A distinct physical click from the PSU itself points to a power delivery short or overload rather than memory. Test with one RAM stick at a time in DIMM_A2 if you want to rule it out, but prioritize power cables and shorts first.
I flipped the PSU switch off and on and it boots again. Is it fixed?
Flipping the switch only resets the latch on the protection circuit. It does not fix the underlying short, overload, or thermal issue. If it clicked once, it will click again under the same conditions. Complete Fixes 1 through 5 to find the root cause instead of relying on the switch reset.
