My QX2710LED monitor suddenly developed four vertical green lines, became noticeably darker, and then started glitching and flickering intensely—almost like a strobe light. The problem was already visible during the computer's boot screen, and the display became nearly impossible to use. After shutting everything down overnight, the monitor now turns on for about a second, switches off, then repeats that cycle continuously. It keeps doing this even when the computer itself is powered off, including an audible sound, and only stops when I unplug the monitor from the wall.
I've restarted the computer, power-cycled everything, and reseated the connections. The monitor uses a V85 AC adapter and was connected to the PC through DisplayPort. I also tested it with an HDMI cable from a Nintendo Switch, but the same power-cycling and flickering occurred. That seems to point more toward the monitor or its power supply than the computer, although I'm not sure.
My system has a Ryzen 5 1600, RTX 3060 Ti, 16 GB of RAM, a B450 AORUS M motherboard, and what I believe is a 500W PSU. The GPU and PSU were upgraded a few months ago. This started while I was playing Outer Wilds. Around the same time, one USB device was repeatedly disconnecting and reconnecting, though it otherwise worked normally. What kind of failure does this sound like—monitor, AC adapter, graphics card, or something else?
2 Answers
The fact that it continues power-cycling with the PC disconnected largely rules out the GPU, DisplayPort cable, and computer PSU. A different input producing the same result rules out DisplayPort as the sole problem too. If a correctly rated replacement power adapter doesn’t fix it, the monitor likely needs board-level repair or replacement.
Since the monitor behaves the same way with the computer turned off and also does it through HDMI from another device, the monitor itself or its external AC adapter is the most likely cause. The green lines, dimming, severe flickering, and repeated on/off cycling are consistent with a failing monitor power circuit or internal electronics. Try a known-good replacement adapter with the exact same voltage, polarity, and sufficient amperage before replacing the display. Don’t keep using an adapter that gets hot, buzzes, or makes unusual noises.
That makes sense. I tested HDMI from a separate device and the monitor still did exactly the same thing, so I’ll focus on the adapter and monitor rather than the graphics card.