I have had a prebuilt gaming PC for a few years. I'm not sure of all the components, but it has an RTX 3070 and a Gigabyte 750W power supply. It was working normally this morning, so I put it into sleep mode before leaving for work. When I came back, it would not turn on at all—there are no fans or lights, and I only hear a brief click when I press the power button. Could the power supply have failed, or is there anything else I should check first?
3 Answers
A flicker of RGB doesn’t rule out a bad PSU. The motherboard can receive a small amount of standby power even when the PSU can’t deliver enough power to start the computer. Disconnect nonessential USB devices and, if you’re comfortable doing so, reseat the main motherboard and graphics-card power cables. If there is still no response, have the PSU tested or replace it with a compatible, reliable unit.
The power supply is the first thing I’d suspect. A failed PSU can result in no fans, no RGB, and just a brief click when you try to start the system. Unplug the PC, switch the PSU off, hold the case power button for about 15 seconds, then reconnect it and try again. Also check the wall outlet, power cable, and PSU switch. If possible, testing with a known-good PSU is the safest way to confirm it. Don’t open the PSU itself.
A power interruption or brownout while the computer was sleeping could have caused the shutdown, and it may potentially corrupt unsaved data. Once the hardware issue is resolved, using a UPS with battery backup for the PC and monitor can help protect against brief outages and voltage drops. However, the UPS would be preventative—the immediate symptoms still point more toward the power supply, power delivery, or motherboard than a normal sleep-mode problem.
I’m not very familiar with the internal components, so I’ll probably start with the basic cable and outlet checks before having the power supply tested.
I did briefly see the RGB flicker once, so I wasn’t sure whether that ruled out the power supply.