Question 1

the lg onscreen control software doesn't detect my monitor, it's just connected with displayport

Accepted Answer

DIAGNOSIS OnScreen Control requires a bidirectional USB connection for detection and control, not just the video signal from DisplayPort or HDMI. You have only a video cable connected. FIX Connect the included USB upstream cable. Locate the square USB-B port on the monitor. Connect the USB-B end of the cable there. Connect the standard USB-A end to an available port on your computer. The monitor now functions as a USB hub. Install the latest OnScreen Control software from the LG website. Launch the software. It should now detect the monitor. IF THAT DIDN'T WORK The specific USB port on your PC may not provide sufficient power or data. Try a different USB port, preferably a USB 3.0 (blue) port on the motherboard's rear I/O. Uninstall the OnScreen Control software. Reboot. Reinstall the software as administrator. Ensure no other monitor control software (e.g., DisplayFusion) is interfering. HEADS UP The USB upstream connection is mandatory for features like screen partitioning (PBP/PIP), precise color calibration uploads, and firmware updates via the software. The monitor's USB downstream ports will only be active when the upstream cable is connected.

Question 2

can i clean the nano ips screen with a microfiber cloth and water or will it ruin the coating

Accepted Answer

DIAGNOSIS The screen has a matte anti-glare coating that can be damaged by harsh chemicals or excessive pressure. Using the wrong cleaner will create permanent smears or strip the coating. FIX Power off the monitor. Use a dry, soft microfiber cloth designed for lenses or screens. Gently wipe the surface in a circular motion. For stubborn smudges, slightly dampen a portion of the microfiber cloth with distilled water. Wring it out completely. It must be only barely damp. Wipe the screen, then immediately dry it with a separate dry portion of the cloth. IF THAT DIDN'T WORK For adhesive residue or oil, use a cleaner specifically formulated for coated LCD/LED screens. Spray the cleaner onto the microfiber cloth, never directly onto the screen. A 70% isopropyl alcohol solution can be used sparingly, but only if applied to the cloth first. Test on a small corner first. HEADS UP Never use window cleaner, ammonia, acetone, or ethyl alcohol. Never use paper towels, tissues, or rough cloths. They will scratch the coating. Apply minimal pressure. The goal is to lift debris, not grind it into the surface. Clean only when the display is cool to the touch.

Question 3

there's a permanent faint vertical line on the left side of the screen, about an inch from the edge

Accepted Answer

DIAGNOSIS This is a hardware fault, specifically a defect in the panel or its internal connections. A persistent vertical line is not a software or settings issue. It indicates a failed column of pixels or a connection issue along the panel's driver board. FIX There is no user fix. You must initiate a warranty claim. Document the issue with a clear photograph. Note the monitor's serial number (found on the back label or in the OSD under General > Information). Contact LG customer support directly or your retailer. The 27GN950-B typically has a one-year parts and labor warranty. Be prepared to provide your proof of purchase. IF THAT DIDN'T WORK Before contacting support, perform a full factory reset to rule out a corrupted firmware setting. Press the joystick. Go to General > Reset. Select Yes. This will not fix a hardware line. If the line disappears during the reset screen but returns in normal use, it is still a panel fault. HEADS UP Do not attempt to disassemble the monitor. This will void the warranty. LG's standard process is often a board replacement or a whole-unit swap via an authorized service center. The repair time can be several weeks.

Question 4

hdr looks washed out and terrible in windows 11 desktop and some games, what am i doing wrong

Accepted Answer

DIAGNOSIS Windows HDR calibration is incorrect or HDR is active in SDR content. The 27GN950-B has an HDR peak brightness of ~600 nits and requires precise settings to avoid a washed-out appearance. FIX First, enable HDR only when consuming HDR content. Turn it off for desktop use. In Windows, go to Settings > System > Display > Use HDR. Toggle to Off. For HDR content, toggle it On. Then, run the Windows HDR Calibration app from the Microsoft Store. Follow the steps precisely. Set the peak brightness slider to 600 nits. Save the profile. IF THAT DIDN'T WORK The monitor's own HDR mode must be set correctly. Press the joystick. Go to Picture > Select Mode. Choose 'Gamer 1' or 'Gamer 2'. Then, navigate to Picture > HDR Effect. Set it to On. Do not use the 'Vivid' or 'Reader' modes for HDR. In the NVIDIA Control Panel, under 'Adjust video color settings', set 'With the NVIDIA settings' and ensure the dynamic range is set to 'Full'. HEADS UP This monitor uses DisplayHDR 600 certification, which is edge-lit. Expect elevated black levels and less impactful HDR compared to Mini-LED or OLED. The 'washed out' look in desktop mode is normal; HDR is designed for mastered content, not the Windows UI.

Question 5

the screen randomly goes black for a second or two then comes back while gaming, especially in hdr

Accepted Answer

DIAGNOSIS This is a signal interruption, commonly caused by an unstable bandwidth handshake. It frequently occurs when using HDR due to the increased data load. The primary suspect is the DisplayPort cable. FIX Replace your current DisplayPort cable. You must use a certified DisplayPort 1.4 (HBR3) cable that is 3 meters or shorter. Ensure the cable is firmly connected. Disable any adaptive sync as a test. Press the joystick. Go to Game Adjust > Adaptive-Sync. Set it to Off. See if the blackouts stop. IF THAT DIDN'T WORK The issue may be related to the GPU driver's handling of DSC with HDR. Perform a clean install of your GPU driver. Use DDU (Display Driver Uninstaller) in Safe Mode to remove the current driver. Install the latest stable driver from NVIDIA or AMD. Do not use a beta driver. HEADS UP If using an NVIDIA GPU, navigate to NVIDIA Control Panel > Adjust desktop color settings > Content type reported to the display. Set it to 'Auto-Select'. A mismatch here can cause repeated renegotiations. Also, avoid using display port splitters or cheap adapters.

Question 6

how do i get 160hz at 4k to work? it's stuck at 120hz or 144hz in windows and nvidia control panel

Accepted Answer

DIAGNOSIS You are not enabling the monitor's maximum 160Hz overclocked refresh rate. It requires two specific settings: DSC (Display Stream Compression) must be active, and the Overclock setting must be turned on in the monitor's own menu. FIX First, enable Overclock on the monitor. Press the joystick. Navigate to Game Adjust > Overclock. Set it to On. The screen will blink. Use a DisplayPort 1.4 cable. On your PC, open NVIDIA Control Panel. Go to Change resolution. Under 'Refresh rate:', select '3840 x 2160 (native)'. The list should now include '160Hz'. Select it. Apply. DSC is automatic and requires no user setting. IF THAT DIDN'T WORK Your GPU may not support DSC. Only NVIDIA RTX 20-series and newer, or AMD RX 5000-series and newer, support DSC for 4K 160Hz. Also, verify your DisplayPort cable is VESA-certified for HBR3 (DisplayPort 1.4). Try a different cable. HEADS UP When Overclock is set to On, the monitor's response time setting (Fast, Faster) may introduce more inverse ghosting. If you see visual artifacts, set Response Time to 'Fast' instead of 'Faster'. The 160Hz mode also increases power consumption and heat output slightly.

Question 7

the back of my monitor makes a faint high-pitched buzzing or whining noise, changes when i move menus

Accepted Answer

DIAGNOSIS This is coil whine from the monitor's internal power supply or circuitry. It is a physical phenomenon, not a defect that affects performance. The sound often changes pitch with varying screen brightness or on-screen content. FIX First, disable any dynamic contrast or power-saving features. Press the joystick. Go to Picture > Energy Saving. Set it to Off. Navigate to Picture > DFC. Set Dynamic Action Sync to Off. These settings modulate power draw and can induce whine. Set a fixed brightness level, ideally between 40-70%. IF THAT DIDN'T WORK The whine may be exacerbated by the GPU's output signal. Try a different refresh rate. In NVIDIA Control Panel or AMD Adrenalin, create a custom resolution with a 144Hz refresh rate instead of 160Hz. Test. Also, try a different certified DisplayPort 1.4 cable. HEADS UP Coil whine is often more audible in quiet environments and can be position-dependent. It does not indicate impending failure. If the noise is loud and constant from day one, contact LG support within the warranty period for a potential unit replacement, as whine severity varies.

Question 8

my new lg ultragear 27gn950-b says no signal on both hdmi and displayport, pc definitely on

Accepted Answer

DIAGNOSIS The monitor is powered but not receiving a valid video signal from your GPU. The most common cause is an incorrect input source selection on the monitor. FIX Use the monitor's joystick button to manually select the correct input. Press the joystick to open the menu. Navigate to Input. Select the port your cable is connected to (e.g., DisplayPort 1). Do not rely on auto-detect. If using DisplayPort, ensure the cable is fully seated at both ends. The connector clicks when secure. IF THAT DIDN'T WORK The GPU driver or output resolution may be incompatible. Boot the PC into Safe Mode. Connect the monitor. Install or update the GPU driver from NVIDIA or AMD. Restart. Also, try setting the PC's output resolution to 1920x1080 @ 60Hz via another display first, then reconnect the 27GN950-B. HEADS UP The monitor's DisplayPort firmware is known to have handshake issues with some GPUs. LG released a firmware update (file name typically '27GN950_27GN950B_VerXX.XX.exe') to address this. You must install it via the OnScreen Control software on a working system.

LG UltraGear 27GN950-B 27 inch 4K Gaming Monitor

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