Replace led with diode - Page 1
Forum section: electronics / beginners

author: Passkewst
author_rank: Newbie
timestamp: September 08, 2021, 09:47:55 pm
content: Hello I have an adapter for HDD SATA 2.5 to USB, there is a LED that I wanted to replace with a diode, how can I find the value of the LED, and know what diode value I need? Thank you

author: xrunner
author_rank: Super Contributor
timestamp: September 08, 2021, 09:53:06 pm
content: Quote from: Passkewst on September 08, 2021, 09:47:55 pmNot sure I understand ... do you mean you want to replace the LED with a different LED (maybe the color)? If not, I don't understand what you are wanting to do.

author: Passkewst
author_rank: Newbie
timestamp: September 08, 2021, 09:58:35 pm
content: Thank you for your answer, I wanted to remove the LED to replace it with a diode to stop having the lighting, but I do not know how to take the value of the LED, I tried the multimeter to take the tension at the terminals of the lighted LED and I'm between 2.1 and 2.3V but I do not know if that's how I have to do

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 08, 2021, 10:00:29 pm
content: There is no general answer to a question like this.It all depends on how the diode is connected.Sometimes they are used as a (rough) voltage reference.Sometimes they are in series with something else. (I had a master-slave switch that did not work without the LED).Most often the're just spreading (unwanted?) light and can be safely removed.-----------------Indeed, somewhere between 1.8V and 2.8V is normal for an LED. It depends on the color. Higher bandgap energy differences emit higher energy fotons, which have different light colors. So the LED color is a pretty good indication for it's voltage drop.A black marker or a piece of duck tape also works.One of my gadgets has a somewhat useful LED, but it was made in the beginning of super bright LED's. My solution was to wrap a piece of white paper around it. It's still visible, but not overwhelming anymore, and the ugly bluish tint is a lot less pronounced.

author: TimFox
author_rank: Super Contributor
timestamp: September 08, 2021, 10:37:21 pm
content: If the LED does something important (rather than illumination), you will have to see what it does before replacing it.Sometimes, an LED is used for a bias voltage, and can be replaced by a low-current shunt regulator, e.g.,TL431 for >2.5 V, orTLVH431 for >1.24 V.

author: james_s
author_rank: Super Contributor
timestamp: September 08, 2021, 10:50:24 pm
content: I would be extremely surprised if the LED has any other function in a device like this. Just remove it and see what happens, I'd say 99.99% chance the device will work just fine.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 09, 2021, 11:17:58 am
content: I agree with James.It's unlikely that it is used in any dual use scenario here, and it can just be removed in this application.I went a bit over the top in my previous post.

author: Zero999
author_rank: Super Contributor
timestamp: September 09, 2021, 12:58:34 pm
content: Place a piece of black sticky tape, over the LED. No soldering, or wire cutting required.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: September 10, 2021, 12:09:48 pm
content: The LED is connected to a + or - directly, check it out.99.99% , what weird HDD is that other 0,01% ?

author: Terry Bites
author_rank: Super Contributor
timestamp: September 10, 2021, 02:35:20 pm
content: This is the only correct answer.Incidendly, I've found if there's something I'd rather not see, I just close my eyes. No soldering either.

author: CharlotteSwiss
author_rank: Frequent Contributor
timestamp: September 10, 2021, 02:46:11 pm
content: in fact the LEDs are annoying where they are not needed; on my pc i covered the leds with black electrician tape, it works great

author: james_s
author_rank: Super Contributor
timestamp: September 10, 2021, 06:53:59 pm
content: I remove them or disconnect them, looks less messy than covering with tape, but it depends on the application. Sometimes I just change the resistor so the LED still works but is much less bright. An indicator should not light up the room.