My PC has a Ryzen 5 5500, RTX 3050 6GB, Gigabyte B450M DS3H motherboard, 8GB DDR4, and a Cooler Master 550W PSU. It has worked for over a year, but my AOC monitor started randomly going black. The computer remains powered on, with fans, lights, and audio still working, but the monitor's power LED turns off completely rather than displaying "No Signal."
A second 720p monitor that had been unused for about four years initially worked normally on the same PC, then developed the exact same problem. It now powers on for roughly a second and shuts off again. I tried different HDMI cables, reconnecting the cables, updating the GPU drivers, and moving the monitors between a power strip and the main power board. Both monitors were connected to the same electrical setup when the failures occurred.
Could the RTX 3050 or the PC's PSU cause a monitor's power indicator to turn off, or is this more likely an issue with the outlet, power strip, monitor power cables, or the monitors themselves? What would be the safest next test to isolate the problem?
3 Answers
The Windows + Ctrl + Shift + B shortcut can reset the graphics driver and may restore an image, but it only helps when the monitor still has power. If the power LED is completely off, focus on the electrical path first. Once the monitor stays powered, you can test the GPU separately with another port, another display, or integrated graphics if available.
Since the monitor’s own power LED turns off, this is probably not an HDMI signal or graphics-card problem. A bad outlet, power strip, extension lead, or monitor power adapter is the first thing I’d investigate. Try one monitor by itself on a completely different wall outlet in another room, with no power strip or extension involved. Also try a known-good compatible power cable if the monitor uses a detachable one.
The RTX 3050 cannot normally switch off a monitor’s power circuitry through HDMI. A graphics problem would usually leave the monitor powered on with a “No Signal” message or its LED in standby. The PSU is also less likely if the computer stays stable, although testing the monitor on a separate circuit is still worthwhile. If both displays fail only on the same electrical setup, stop using that power strip until it has been checked or replaced.
The fact that the second display worked at first doesn’t rule out the shared power setup. A failing strip, loose plug, or bad outlet can work intermittently and then drop power under certain conditions.
I don’t use a UPS, just a multi-outlet power box, and the PC keeps running when the monitors shut off. I also tried replacing the extension lead, but the problem still happened.