Question 1

can i mount this on a vesa arm? the stand takes up so much room and i don't see any screw holes.

Accepted Answer

DIAGNOSIS You can, but it's not straightforward. The LG 27MQ400-B does have VESA mount compatibility (100x100mm), but the screws and the interface are hidden behind the stock stand. FIX To access the VESA holes, you need to remove the default stand. Lay the monitor face down on a soft, flat surface. Firmly grip the stand neck where it meets the back of the monitor. There's a release mechanism—you need to press a small plastic tab (usually located at the top of the junction) inward while pulling the stand straight down and away from the monitor. It should detach. Once off, you'll see the four VESA screw holes and a plastic cover plate in the center. Remove that plate, and you can attach your VESA arm using the appropriate screws (typically M4 x 10mm length, but check your arm's instructions). IF THAT DIDN'T WORK If the stand won't budge, don't force it. Double-check for a locking lever or button. There are official LG tutorial videos for this process—search "LG monitor stand removal" for a visual guide. Using the wrong screws or over-tightening can damage the internal threading. HEADS UP The monitor is very light, so most arms will handle it fine. Once the stand is off, there's no way to re-attach it without the VESA bracket, so make sure you're committed to the arm or store the stand safely.

Question 2

is there a way to make the text look sharper? everything seems a little blurry or fuzzy on this 1080p 27 inch screen.

Accepted Answer

DIAGNOSIS At 27 inches and 1920x1080 resolution, the pixel density is relatively low (about 82 PPI). This can make text and fine details appear less sharp than on a higher-PPI screen, but fuzziness often points to a scaling or sharpness setting issue. FIX First, press the joystick and go to the OSD. Navigate to Picture > Picture Adjust > Sharpness. The default is 50. Try increasing it to 60-65. Don't go too high (above 70), or you'll get ugly edge artifacts. Next, on your computer, ensure it's set to the monitor's native resolution (1920x1080). In Windows, right-click desktop > Display settings > Scale and layout. Try setting Scaling to 100%. IF THAT DIDN'T WORK Use Windows ClearType. Search for "Adjust ClearType text" in the Start menu and run the wizard. It will walk you through picking the text rendering that looks best to your eyes. This makes a big difference for text clarity specifically. HEADS UP This is the inherent trade-off of a large 1080p screen. For razor-sharp text, you'd want a 1440p or 4K monitor at this size. The fuzziness you're noticing is likely the visible size of individual pixels, which settings can improve but not eliminate.

Question 3

the screen keeps going black for a second and then coming back, like it's losing signal, while i'm just working normally.

Accepted Answer

DIAGNOSIS This is typically a handshake issue between the monitor and your computer's graphics card, often related to the HDMI cable or the monitor trying to sync to an unstable signal. FIX Start with the cable. If you're using the included HDMI cable, try a different, high-speed HDMI cable that you know is good. Ensure it's fully seated at both ends. Next, on the monitor, open the OSD with the joystick. Go to General > HDMI Compatibility Mode and turn it ON. This can stabilize the signal with some older or finicky graphics sources. IF THAT DIDN'T WORK The issue might be on the PC side. Update your graphics drivers. Also, in Windows, go to Power & sleep settings and make sure the display isn't set to turn off after a short time. Disable any adaptive sync settings in your graphics control panel, as this basic monitor doesn't support FreeSync or G-Sync. HEADS UP If you're using a cheap HDMI switch, splitter, or dock, that's the most likely culprit. Try connecting the monitor directly to your computer's port to rule that out.

Question 4

how do i clean the screen on this thing? the lg site says not to use glass cleaner but it's just glass right?

Accepted Answer

DIAGNOSIS It's not just glass—it's a glass panel with a matte anti-glare coating. Harsh chemicals like ammonia or alcohol in standard glass cleaners will permanently damage and strip that coating, creating cloudy, smeared patches. FIX Power off the monitor and let it cool. Use a dry, soft, microfiber cloth (like the kind for glasses or cameras) to gently wipe away dust. For fingerprints or smudges, slightly dampen a part of the microfiber cloth with distilled water only. Wipe gently in a circular motion, then immediately dry the area with the dry part of the cloth. Never spray liquid directly onto the screen. IF THAT DIDN'T WORK For stubborn spots, you can use a monitor-specific cleaning solution that explicitly states it's safe for anti-glare coatings. Apply a tiny amount to the cloth, never the screen. Isopropyl alcohol (70% or less) is sometimes recommended for glossy screens, but it's a gamble on this matte coating—I'd avoid it. HEADS UP Don't use paper towels, tissues, or rough cloths—they can microscratch the coating. The damage from wrong cleaners isn't always immediate; it can appear as a gradual, permanent haze.

Question 5

i hear a faint but annoying high-pitched whine or buzz from the back of my monitor, is this normal or should i return it?

Accepted Answer

DIAGNOSIS That's likely coil whine from the monitor's internal power supply or components. It's not "normal" in the sense of being intended, but it's a common electronic phenomenon and usually isn't a sign of impending failure. FIX First, identify when it happens. Is it constant, or only when the screen is very bright (like a white webpage) or when it's at a specific brightness level? Try adjusting the monitor's brightness via the OSD (not your computer's settings) up or down a few notches. Sometimes changing the refresh rate (in Windows display settings) from 75Hz to 60Hz or vice versa can shift the electrical load enough to stop the noise. IF THAT DIDN'T WORK Check your power source. Try plugging the monitor into a different wall outlet or a surge protector, away from other high-draw devices. A dirty or unstable power supply can exacerbate coil whine. HEADS UP If the buzzing is loud enough to hear over ambient room noise from a normal sitting distance, and it's new, it could be a defect. Contact LG support while under warranty—they may consider excessive audible coil whine a valid reason for a repair or replacement.

Question 6

the colors on my lg monitor look really washed out and flat compared to my laptop screen, how do i fix that?

Accepted Answer

DIAGNOSIS The monitor is likely using a default picture mode (like "Reader") that prioritizes low blue light over color vibrancy, or your graphics driver is outputting a limited color range. FIX Press the joystick on the back of the monitor to open the OSD menu. Navigate to Picture > Picture Mode. Change it from "Reader" or "sRGB" to "Custom". Then, go into Picture Adjust and you can tweak Brightness, Contrast, and Sharpness to your liking. For a quick fix, the "Vivid" mode will pop the colors a lot more, but it can look oversaturated. IF THAT DIDN'T WORK The issue might be on your computer's end. On Windows, right-click the desktop, go to Display settings > Advanced display > Display adapter properties for Display 1. In the new window, go to the Color Management tab and make sure sRGB is the profile. Also, in your graphics card control panel (NVIDIA/AMD/Intel), look for a setting like "Dynamic Range" and set it to "Full" instead of "Limited." HEADS UP This is an IPS panel, so viewing angles are great, but its color gamut is standard sRGB. It won't match the punchiness of some high-gamut laptop screens, so temper your expectations after calibration.

Question 7

the power button on my lg 27mq400 feels super mushy and sometimes i have to press it like 5 times to turn it on, is it broken?

Accepted Answer

DIAGNOSIS The tactile membrane switch behind the power button is likely failing or has become unresponsive due to wear or a minor manufacturing defect. It's a known weak point on this model's joystick control assembly. FIX Unfortunately, the power/joystick nub is a single unit. Before you go deeper, try pressing it more deliberately—use the tip of your finger and press straight in, not at an angle. If it's consistently unresponsive, your real fix is to use the monitor's auto-wake feature. As long as the PC is sending a signal, the monitor should turn on automatically when you wake your computer. To turn it off, you can just shut down your PC and the monitor will eventually go into standby. IF THAT DIDN'T WORK If it's under warranty, contact LG. If not, and it's truly unusable, the control board (which the joystick is part of) would need replacement. It's not a user-serviceable part without disassembling the monitor, which voids warranty and is tricky. HEADS UP Don't keep mashing it harder—you could damage the internal connection further. The auto-wake/sleep with your PC's power state is the best workaround.

Question 8

my new lg 27mq400 monitor just says 'no signal' even though my hdmi is plugged into my laptop, what am i missing?

Accepted Answer

DIAGNOSIS The monitor is powered on but not receiving a video signal from your source. The most common culprit is the laptop not being set to output to the external display. FIX Yeah, this one's common. First, make sure the HDMI cable is firmly plugged into the monitor's HDMI port (it's the one on the back, usually the only one unless you're using an adapter). On your laptop, you need to trigger the display output. For Windows, press the Windows key + P and select "Duplicate" or "Extend." For a Mac, go to System Settings > Displays and make sure it's detected. If it still doesn't show, try a full power cycle: turn off the monitor, unplug it from the wall for 30 seconds, and restart your laptop. IF THAT DIDN'T WORK Try a different HDMI cable if you have one. The port on the monitor itself is pretty robust, but a flaky cable is always a possibility. Also, check your laptop's graphics control panel (like NVIDIA or AMD software) to see if the output is disabled there. HEADS UP This monitor doesn't have a VGA port, so if you're using an old VGA-to-HDMI adapter, that might be the issue—those adapters can be finicky and often need active conversion.

LG 27MQ400-B 27 inch Full HD IPS Monitor

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