My PC has a Ryzen 5 5500, RTX 3050 6GB, Gigabyte B450M DS3H motherboard, 8GB DDR4 RAM, and a Cooler Master 550W PSU. It has worked for over a year, but recently my AOC monitor began randomly going black. The computer itself stays powered on—the fans, lights, and audio continue working—but the monitor's power LED turns off completely rather than displaying a "No Signal" message.
AOC agreed to replace the monitor, so I tested an older 720p monitor that had been unused for about four years. It worked normally at first, but eventually it suffered the exact same problem: the screen and power LED shut off, and pressing its power button only turns it on for about a second before it switches off again.
Both monitors were connected to the same power board. I also tried connecting one directly to the power board instead of using the extension board, but the issue remained. I have already updated the graphics drivers, changed the HDMI cable, and reseated the HDMI connection at both ends.
Could a faulty RTX 3050 or its HDMI port cause a monitor's power indicator to shut off, or would that normally only cause a loss of video signal? Could the PC's PSU somehow be responsible even though the computer continues running? What should I test next to determine whether the problem is the monitors, the power board or wall outlet, the GPU, or the PSU?
3 Answers
Since the monitor’s own power LED goes out, this sounds more like an AC power problem than an HDMI or graphics-card problem. Try running a monitor from a completely different wall outlet, preferably in another room, with no shared power board or extension. If both monitors are plugged into the same strip or outlet, a failing strip, loose connection, or overloaded protection circuit could affect both.
If the monitor is still powered but only the image disappears, press Windows + Ctrl + Shift + B. Windows should beep and reload the graphics driver. If the image returns, investigate the driver or GPU. However, that shortcut will not fix a monitor whose power light has completely gone out, so the outlet, power strip, cable, or monitor power supply should be checked first.
The RTX 3050 and the computer’s PSU generally cannot directly switch off a monitor’s power LED. A graphics problem would usually leave the monitor powered on with a “No Signal” message. Test the monitor by itself on a different wall outlet and, if possible, use a different power cable. Also try another known-good monitor on a separate outlet. If the monitor still turns off after a second, the monitor or its power circuitry may be failing.
I replaced the extension cord and also tried connecting the monitor directly to the power board, but the same behavior happened.
I don’t have a UPS. I’m using a power box with several sockets, and the PC keeps running normally when the monitor turns off.