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  1. #41  
    Quote Originally Posted by jdale View Post
    Not visible on my Pre3.

    It's not uncommon for infrared LEDs to produce some visible red light. On infrared illuminators you especially see this when the intensity is turned up all the way. The visible part is, obviously, in the visible spectrum and not infrared, but that doesn't mean that it is not being produced by an IR LED. Just that the frequency range of the IR LED is not as tight as you might think. The visible component is much lower intensity than the IR component.

    It's possible that the IR LEDs used for the proximity sensor are not exactly the same in all models. I'm going to go out on a limb here and say that I think this is more likely than the hypothesis that some Pre3 owners have superhuman sensory abilities....
    Whilst this sounds plausible and would explain why some LEDs in a batch produce the visible light and others don't I thought that LEDs generally work by the semiconductor junction emitting a single frequency of light. This is why it is so hard to make white LEDs and these generally work by cheating and getting a secondary material to re-radiate at wider frequencies than the initial emitter.

    Since all that is required in this case is a single frequency emitter (in the IR range) why would they go to the bother of using one that can emit multiple frequencies?

    I should add that my knowledge of LEDs goes back to my uni years some 25 years ago (when blue LEDs were all but non-existant), I have tried to keep up with the changes since but it is possible I have missed something important that would relate to this case.
  2.    #42  
    Quote Originally Posted by blue duck butter View Post
    So I think I figured out what causes this. There was no light on mine previous to using the webOS doctor. After I had to doctor, the light appeared. It appears something in the 2.2.3 webOS doctor made this happen.
    Good find, but my spare pre3 has never even been activated let alone doctored, so I am chalking this one up to the doctor unlocking your superhuman abilities.

    -- Sent from my Palm Pre3 using Forums
  3. #43  
    Damm! I also have Super-Human Powers! And my whife! And our son! And the cat (no, we do not have one, but if we had, it wouldl!)
    We both see it, by changing batteries, on our both Pre3. And it is different from the IR faint light you can see sometimes (depending on light conditions, inclination, mood, etc).

    IMHO, it is a bug. Probably, at start up, the circuits get more energy than they really need. This makes that the IR-LED get more current (or voltage) than it needs, thus lightning up (nearly burning, in my opinion).

    I mean, if you haven't saw it, you will not understand. It is plain red, seems to be, really, a power indicator LED. In fact, can be that there is a second LED, or a double LED (with more colours). Like someone said here before, we do not know what components PALM/HP is using, and worst, what they get for what they paid for!

    Perhaps was a second type or kind of notification, who knows? In any case, I was happier when I though I had Super-Human Powers! Or just a kind of! :-) :-)))
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    #44  
    Quote Originally Posted by andyhurley View Post
    Whilst this sounds plausible and would explain why some LEDs in a batch produce the visible light and others don't I thought that LEDs generally work by the semiconductor junction emitting a single frequency of light. This is why it is so hard to make white LEDs and these generally work by cheating and getting a secondary material to re-radiate at wider frequencies than the initial emitter.
    If you look at the spectral curves here Light-emitting diode - Wikipedia, the free encyclopedia you'll see they are pretty tight, but not perfect.
  5. #45  
    Quote Originally Posted by jdale View Post
    If you look at the spectral curves here Light-emitting diode - Wikipedia, the free encyclopedia you'll see they are pretty tight, but not perfect.
    I just saw it after swapping the SIM card. It came up immeditely after powering on my Pre3, and dissapeared again at some point during the phone boot cycle.
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    #46  
    Quote Originally Posted by Excimer View Post
    Fellas -

    I am an ophthalmologist working for industry (laser vision lasers). Infrared light is NOT visible by the human eye. Period. There is a near infrared part of the light spectrum that is closest to the vibrant visible red (710 to 750 nm) part of the visible spectrum but infrared light (NWIR near wavelength infrared, MWIR medium wavelength infrared and LWIR long wavelength infrared) is never visible to the human eye unaided. So... if you are human and if you are able to see it - it is not infrared. Just a fact.
    . . . . . you're not human . . . . . .

    :-)
  7. #47  
    Quote Originally Posted by roneyii View Post
    I've been wondering about this since the first day I got my Pre3.
    Glad enough of them are out now that other people have seen it too.

    Maybe we're not Human...
    Guys the red light is the reflective light from the proximity sensor. It is not infrared and you can see it with your eyes.
  8. #48  
    My unlocked AT&T Pre3 just started displaying this red led today today during reboots, yet I've had it for nearly a year now... Anyone managed to hash out what triggers it?
  9. #49  
    Hello guys... this thread has been dead for a long time. found it while looking to find if i could use that led as notification signal through a patch...

    Here is the best part: The small notification in LED red are the letters "hp"...
    Weird that nobody could notice it. Looking at the first pictures posted, we can make out that it is not one light but maybe two bubbles... It is very fine print, but you can read hp if you try to focus enough...

    Anyways, got a used pre 3 last month and am loving it...

    Anyone in india who has a dead pre3 and can sell it to me -IF i can use it as a spare charger/battery??
  10. #50  
    I remember this thread. Had some good laughs in the older posts.
  11. #51  
    Quote Originally Posted by vasekvi View Post
    i have 2 at&t pre3s, one i use as a spare battery charger and the other as my phone. One day as i was swapping batteries i noticed a red light that looks like an led coming from my spare phone's proximity sensor area. I tried to take a picture of it but it turned off within 20 seconds and i had a hard time focusing on it. So i kept a camera handy to see if it would ever happen again.

    Just tonight, the phone i used did the same exact thing as i did a battery swap right when i went to power it up. So now i can confirm that this was not just an anomaly with the spare phone. So the only way to replicate this that i have seen is to insert a battery into the phone and power it up, and i have only seen this twice.

    Has anyone else noticed this? Can anyone speculate as to what this light is for? It would be pretty neat if there was some other led we could use to access as another type of notification light. Here are the best pictures i could take in the time i had. In actuality, the light is not that bright. It looks like a little pinpoint light its not really bright and its not all that noticeable unless you happen to be looking.

    click to view quoted image


    click to view quoted image
    it is the ir led of the proximity sensor
  12. #52  
    whitman wanted it to resemble a pez dispenser...
  13. #53  
    Can I enable or disable the red light? using Mojo
  14. #54  
    I just felt like resurrecting this thread to say one of my Pre3s emitted this red light the last time I pulled the battery to remove or install a SIM. Nice to see I have finally developed my superpowers too.
  15. #55  
    I've also seen this on occasion - and I'm not just saying it to be in the special club!

    I don't think it's IR because of what was previously posted by excimer and I don't think the light is 'leaking' to a visible wavelength - because then it would be seen whenever the proximity sensor was active. That's presumably at least when the phone app is up - which would mean everyone would notice it often. Remember, a battery pull is one way to fix a crashed phone and maybe this is simply indicating a 'cold' boot. Perhaps there's a difference in rebooting with a connected battery and booting after pulling the power. I'm assuming that it's a joke that the light spells 'HP'.

    So it probably doesn't matter, but being able to replicate the circumstances under which the light appears might give a clue as to it's purpose, then being able to light it at will, you could get a magnifier to see if the light contains letters!

    ...or maybe...call me crazy... this light was installed in the confident hope that webOS would rule the world and when Blackberry failed, was bought by HP and got webOS ported to it's devices, then webOS could use the famous Blackberry notification LED! Unfortunately, Mark Hurd's secret plan to get Leo Apotheker appointed as Blackberry CEO was misread by the HR department and the rest is history...

    Hmmm... that might have been a better April fool than the one I actually published..!
  16. #56  
    I sure its a enginnering debug LED, shows the phone has cold booted, and ready to boot firmware etc, before screen boots. Maybe red LED was first test pass for first firmware install. Shame their no enginners from Palm to let us know.
    Its sure is fun topic. Is not red LED first sign of self aware artificial inteligence, (terminator / cyclon etc) its trying too wake and take over.

    LED lights are still the cheapest and easiest way to get indication its working
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