Question 1

can i clean the matte screen on this thing? the microfiber cloth just smears it and makes it look worse.

Accepted Answer

DIAGNOSIS The anti-glare coating on the IPS panel is porous. Dry dusting or using a dirty cloth pushes oil and debris into the coating, creating smears. FIX Use a clean, lint-free microfiber cloth designed for glasses or lenses. Lightly dampen a section of the cloth with distilled water only. Wipe the screen gently in a single direction. Immediately dry the area with a dry section of the cloth using straight, overlapping strokes. IF THAT DIDN'T WORK For stubborn smudges, use a 50/50 mix of distilled white vinegar and distilled water. Apply sparingly to the cloth, not directly to the screen. Test on a small corner first. The acetic acid can break down oils without damaging the coating. HEADS UP Never use window cleaners, alcohol, ammonia, or abrasive cloths. They will permanently damage the anti-glare coating, leaving shiny, blotchy patches. Never spray liquid directly onto the screen, as it can seep into the panel edges.

Question 2

the screen has a weird flicker or tearing in the middle when i play games, even with freesync turned on.

Accepted Answer

DIAGNOSIS This is likely a conflict between the game's frame rate, the monitor's Adaptive-Sync range (48-75Hz), and the graphics card's settings. FIX First, confirm Adaptive-Sync is on. Use the monitor's joystick: go to Game Adjust > Adaptive-Sync and set to On. In AMD Radeon Software, ensure FreeSync is enabled for the display. In NVIDIA Control Panel under Display > Set up G-SYNC, check "Enable G-SYNC, G-SYNC Compatible" for this monitor. IF THAT DIDN'T WORK The tear line indicates frames are exceeding the 75Hz max refresh rate. Cap your in-game frame rate to 73 FPS using the game's settings or the graphics driver's frame rate limiter. Do not rely on V-Sync alone. HEADS UP This monitor's Adaptive-Sync range is narrow. If your game's frame rate drops below 48 FPS, Adaptive-Sync disengages, causing stutter. Use in-game graphics settings to maintain a minimum FPS above 50.

Question 3

the monitor won't wake up from sleep when i move my mouse, i have to press the power button every time.

Accepted Answer

DIAGNOSIS This is a failed wake-up signal handshake, commonly due to the computer's power management settings or a deep sleep state on the monitor. FIX First, disable the monitor's deep sleep. In the OnScreen Control menu, go to General > Power LED and set it to On. If using a desktop, check the PC's Power Options. Go to Edit Plan Settings > Change advanced power settings. Under PCI Express, set Link State Power Management to Off. IF THAT DIDN'T WORK The issue is often specific to the input cable. For DisplayPort, ensure the cable is DP 1.4 certified. Try a different cable. For USB-C, the issue is frequent. Switch to using an HDMI cable for the video connection while using USB-C only for peripheral passthrough. HEADS UP If the monitor's power LED is off (not blinking), it is in a mechanical off state. This happens if it loses AC power or is unplugged while the computer is off. You must press the button to restore power.

Question 4

how do i get the picture-by-picture (pbp) mode to work? i have two computers connected but can't split the screen.

Accepted Answer

DIAGNOSIS PBP mode has specific active signal requirements. It will not activate if one input is idle or in sleep mode. FIX Connect the two source devices to two different inputs on the monitor, e.g., USB-C for laptop 1 and HDMI for laptop 2. Ensure both computers are awake and outputting a signal. Press the joystick, navigate to Picture > Screen Split, and select PBP. Choose the two input sources to display. IF THAT DIDN'T WORK The monitor may be defaulting to a resolution/refresh rate that is incompatible in split mode. On the source device, manually set its output resolution to 1720 x 1440 (half of 3440 x 1440) at 60Hz before enabling PBP. HEADS UP In PBP mode, advanced features like Adaptive-Sync, HDR, and specific color gamuts are disabled. The USB-C downstream ports and audio-out will only be associated with the input selected as Source 1 in the PBP menu.

Question 5

there's a constant faint high-pitched whine or buzz coming from the back of the monitor, is this normal?

Accepted Answer

DIAGNOSIS This is coil whine from the monitor's internal power supply or voltage regulators. It is a physical characteristic, not a defect, but its audibility varies by unit and ambient noise. FIX The whine often correlates with brightness. Open the Picture menu and adjust Brightness down from 100. Test at 80, 60, and 40. The noise frequency and volume will change. Find a brightness level where it is inaudible in your environment. IF THAT DIDN'T WORK The whine may be exacerbated by a specific input signal. Switch from DisplayPort to HDMI or vice-versa. Also, try setting the refresh rate to 60Hz instead of the default 75Hz via your computer's display settings to see if it changes. HEADS UP Coil whine does not indicate impending failure. It is not covered under warranty unless deemed excessive. If the sound is a loud buzzing or crackling, that is different and may indicate a faulty component.

Question 6

the colors on my new lg ultrawide look washed out and dull compared to my old monitor, especially blacks.

Accepted Answer

DIAGNOSIS The default picture mode is likely set to a low-contrast, energy-saving preset. The IPS panel's native contrast ratio is 1000:1, which can appear muted if not configured. FIX Press the joystick to open the main menu. Navigate to Picture > Picture Mode. Change from "Reader" or "sRGB" to "Custom". Then go to Picture > Brightness and adjust Contrast to 70 and Black Level to 55 as a baseline. Ensure Gamma is set to Mode 2. IF THAT DIDN'T WORK The washed-out look may be from the graphics card outputting a Limited (16-235) RGB range. On an NVIDIA card, open NVIDIA Control Panel, go to Display > Change resolution, and set Output dynamic range to Full. On AMD Radeon Settings, go to Display and toggle the HDMI/DCP pixel format to Full RGB. HEADS UP Do not use the HDR Effect mode for standard content. It artificially boosts contrast and will crush shadow detail. True HDR content requires enabling HDR in Windows Display Settings, but this monitor has limited HDR10 capability (350 nits peak).

Question 7

just got this monitor and the usb-c connection won't charge my laptop, it just shows the screen. what's wrong?

Accepted Answer

DIAGNOSIS The USB-C port is not delivering the expected 60W of power. This is typically a cable or source device compatibility issue, not a monitor hardware fault. FIX First, verify the cable. You must use the cable included with the monitor or a certified USB-C 3.1 Gen2 cable that explicitly supports 100W Power Delivery. Check the laptop's power requirements. The 34WN80C-B port maxes out at 60W. If your laptop requires more, it will not charge. IF THAT DIDN'T WORK The monitor's USB-C Power Delivery negotiation may have locked up. Power cycle the monitor completely: unplug it from the wall outlet for 60 seconds. Reconnect and retry. HEADS UP Some laptops, like certain Lenovo or Dell business models, use proprietary charging protocols. They may only charge from their own power adapter, even over USB-C. Check your laptop's manual for USB-C PD compatibility.

Question 8

my lg 34wn80c monitor goes black for a few seconds randomly while i'm using it, then comes back. what is this?

Accepted Answer

DIAGNOSIS This is the monitor's built-in power-saving feature activating incorrectly due to a faulty signal detection handshake. It misinterprets a steady input as no signal. FIX Navigate to the monitor's OnScreen Control menu. Go to General > Energy Saving and turn the setting to Off. Disable any Eco Mode or Screen Off timers in the same menu. For a connected Mac, also go to System Settings > Displays > Advanced and turn off "Allow display to sleep." IF THAT DIDN'T WORK The issue may be a failing or low-quality DisplayPort cable. Replace the cable with a certified VESA DisplayPort 1.4 cable. If using the USB-C connection, try a different, high-bandwidth USB-C cable capable of video and power delivery. HEADS UP This issue is almost always the monitor's software, not the computer's graphics driver. Updating the monitor's firmware requires a Windows PC and the LG OnScreen Control application.

LG 34WN80C-B 34 inch UltraWide USB-C Monitor

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