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Can I break my monitor's LED? (lemy.lol)
submitted 10 months ago by [email protected] to c/ece
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I own a Samsung monitor, and when it's in standby mode the LED blinks all night. My hearing is so sensitive, and my room so quiet, that I can actually hear the LED powering on and off.

So, every night I power it off manually. Sometimes I forget as I turn my PC off, and as I'm laying comfortably in bed, falling asleep, I hear it cycling, so I have to get out of bed, walk over, and turn it off, which delays my sleep.

At this point I'm tempted to take off the bottom panel and break the LED with a screwdriver, but I'm worried that this might change how the current flows through the monitor's circuit board.

I would appreciate any advice, suggestions or insights, thanks in advance!

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[–] [email protected] 12 points 10 months ago (1 children)

The LED doesn't make any noise. The only thing you could be hearing is a faint whine from the power supply current changing, although I'm surprised that an LED would have enough of an effect to noticeably change the sound.

Removing the LED will not damage anything. No reputable product would be designed so poorly that a small decrease in current would break something. Depending on where the LED is though, breaking/disconnecting it could be far more trouble than it's worth, and you might risk damaging other parts of the monitor trying to get to it.

I would agree with the other commenter, your effort is probably better spent on something to help you remember to turn the monitor off. Or, even just buy a smart outlet and plug your monitor into that, so that if you forget, you can use your phone to power off the monitor without getting out of bed.

[–] [email protected] 2 points 10 months ago

I made this same post in another community. A user there said that removing the LED may prevent the power from being drawn to that component, thus eliminating the sound. Do you think that's the case?

[–] dhork 5 points 10 months ago (2 children)

Get a smart plug that you can control from your phone?

Bonus points if you install Home Assistant on a Raspberry Pi and configure the plug to turn on and off automatically based on the sunset time in your area combined with the moon phase....

[–] [email protected] 1 points 10 months ago

Looking into doing this, thanks for your advice.

[–] kn33 -1 points 10 months ago

More realistically useful: a button under your bed hooked to HA that turns it off when you're in bed

[–] [email protected] 4 points 10 months ago (1 children)

Just to make sure... Did you check whether the LED can be turned off in the monitor settings?

If that is not the case, I would suggest getting a smart plug, and specifically one that can monitor the power consumption. That way you can automate it in such a way that it switches the power off when the power consumption drops below a certain value and stays there for a bit. I set this up in multiple locations in the house and it helps save on standby power usage. I use node-red to monitor and control the plugs, but other options like Home Assistant would work as well.

The plugs (Shelly) I use even have the option to set up the automation in the app (which requires cloud connection to be enabled), or run scripts on the devices themselves (no cloud required, but not all their devices support local scripts. You typically need the newer "plus" devices for that. You can then easily set up an automation that switches the plug off if it is powered on and the power consumption stays below 10W for 5 minutes for example. You could put your whole desk on that plug, which should save you some money on your energy bill as an added bonus.

[–] [email protected] 1 points 10 months ago

Thanks for your tip, I'm already looking into installing Home Assistant. I think I can configure it to turn the monitor off at the plug after my PC is shutdown, thanks for your suggestion.

[–] superbirra 2 points 10 months ago

I made a script which turn my monitors off by sending a couple of DDC commands via ssh from termux so I can do this from my phone while in bed. Via ddc you can turn them off like the button press, not sleep

[–] [email protected] 2 points 10 months ago (1 children)

Do the lazy and safe thing; Electrical tape over the light.

[–] [email protected] 6 points 10 months ago (2 children)

Light isn't the issue. It's the sound of it cycling.

[–] dohpaz42 3 points 10 months ago

Easy: turn the faucet in your bathroom on to drip. The sound of the water dripping should drown (pun intended) out the sound of the monitor. (Kidding of course).

You could try ear plugs when you sleep.

[–] agent_flounder 1 points 10 months ago (1 children)

Maybe a white noise generator would help?

Or listen to a lot of extremely loud music ... I wished I had half your hearing acuity.

[–] [email protected] 1 points 10 months ago

Half is probably the sweet spot. Trust me, you do not want to be this sensitive to sound. I would love to give away half of my sensitivity to you.

Ironically, I also have tinnitus and misophonia, so sleeping for me is like sleeping for you, with the lights turned on just enough to bother you.

[–] CharlesMangione 2 points 10 months ago (1 children)

I strongly recommend against it as you will probably break your monitor trying to get the sealed case open, but if you did get to the LED and cut it out, measure the resistance, and replace it with a resistor of similar resistance, that should nip any changes to current flow in the bud. Again, I stress, the most likely thing that happens here is you break your monitor trying to open it.

Personally, I recommend you just set a reminder to turn it off before you go to sleep.

[–] agent_flounder 9 points 10 months ago (1 children)

The thing is LEDs are non-linear devices; they don't really follow Ohm's law and you can't measure the resistance with an ohmmeter.

If you want to sub a resistor to ensure the same current draw you could measure the LED current and voltage drop in circuit and then calculate what resistor to use in its stead.

I wouldn't worry about it, though. Most standard indicator LEDs run less than 20mA (because that's often their max rated current and to extend their lifetime, designs usually run LEDs well below that limit). I can't imagine any sane design that would blow up if that load wasn't present.

[–] CharlesMangione 1 points 9 months ago* (last edited 9 months ago)

Yeah well that's what I get for giving electrical engineering advice with an electrician's education. I should go to school.

[–] Psaldorn -2 points 10 months ago (1 children)

Just put a bit of sticky tack on it. If you need it to blend in, paint the putty out use black marker.

Then it's still removable if you want to sell it later

[–] [email protected] 2 points 10 months ago (1 children)

Did you stop reading the post after the first sentence?

[–] Psaldorn 2 points 10 months ago (3 children)

Putty can block sound if it's covering the thing emitting that sound? The visual parts were just there because it might be unsightly

[–] [email protected] 3 points 10 months ago (1 children)

I genuinely cannot believe this shit.

IT FUCKING WORKED!

Giant blob of Blu Tack over the light and the sound is in-audiable.

You're a fucking legend, love you forever.

[–] Psaldorn 2 points 10 months ago

🧡

[–] [email protected] 2 points 10 months ago

I'll give it a go, no harm in trying. Though, my intuition tells me the frequency of the sound will emit through the plastic covering the front.

[–] [email protected] 0 points 10 months ago

covering the thing emitting that sound

You're implying that the LED itself is emitting sound. Obviously that's not the case. Not that covering one side of an isotropic sound source would even mute it