Author Topic: General LED failure question  (Read 753 times)

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Offline msuffidyTopic starter

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General LED failure question
« on: May 03, 2023, 06:42:05 pm »
I got this free TP-Link Archer C9 v2 router.

It has 8 LED status lights. There seems to be 2 banks of them, and the right 4 of the 8 are working properly. None of the other ones work, but you can barely see a dim light coming from them. My theory is something has failed closed and thus is sucking the power out of the left bank. Another theory is there is something wrong with what is supplying the power to those LEDs. The router otherwise works properly. So I am wondering is there is any overheating/power loss possible in this case, or are these designs someone done to eliminate those problems?

Here is the V3 pcb. I can not find  a photo for the V2 one.
 

Offline PlainName

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Re: General LED failure question
« Reply #1 on: May 06, 2023, 03:16:49 pm »
What is driving the LEDs?

That photo is pretty much like showing a photo of the Canary Wharf tower and asking why the lifts on the left don't work.
 
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Offline jwet

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Re: General LED failure question
« Reply #2 on: May 09, 2023, 08:06:04 am »
Agree w/PlainName- LED's aren't complex, they're dim because they're under driven or burned out.
 

Offline msuffidyTopic starter

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Re: General LED failure question
« Reply #3 on: May 10, 2023, 04:28:52 pm »
I don't have a schematic and don't want to really take it apart so that is as far as I can really go. I just hope there isn't a non limited short in there.
 

Offline tooki

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Re: General LED failure question
« Reply #4 on: May 10, 2023, 05:26:04 pm »
If you power it on without the case on, do the LEDs light normally?

Just to rule out something simple like the PCB not being aligned correctly with the case, such that the LED light pipes aren’t in the right spot.


P.S. I find it somewhat amusing that the thread title is “general LED failure” but the question is then extremely specific! :p
 

Offline james_s

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Re: General LED failure question
« Reply #5 on: May 10, 2023, 05:38:16 pm »
Test the LEDs with the diode test function on a multimeter, or use a current limited source such as a 9V battery in series with a 1k resistor and connect it across each LED to see if they glow. I've had LEDs fail on a handful of occasions, the blue (and blue-based phosphor colors) ones seem especially prone to this, they get dimmer and dimmer over time.
 


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