Testing LED's

[jcoffin1981]

After resoldering a board there are 5 LEd's that are not functional.  Sure it's possible that some are not making proper contact somewhere or that they just did not survive the trauma.  I ordered a 10 pack of LED's which I'm waiting and I have a couple that are lying around.  I'm trying to figure out a way to test them and ran wire from a 1.5V button battery and from a AAA battery to the contacts and they did not light up.  They could be broken or I'm just not doing it right. 

Is there a tried and true way for testing before reinstalling.  I do not want to solder and desolder several times.

[tp4tissue]

/headscratch


assuming the traces on the board  isn't the problem..  you can just use the multimeter put it on resistance, and it will light up the led.

they only work in 1 direction.

[Tactile]

There are lots of LED testers on Ebay starting at just a few dollars.

[tp4tissue]

There are lots of LED testers on Ebay starting at just a few dollars.

Really.. come on guys,  you don't need to spend money to do this..

[jcoffin1981]

Yes, I'm sure that they are all in the same direction.  There was once or twice that I forgot to disconnect the usb cord and touched a switch contact with the iron.  Maybe I overloaded a few of the LED's.  As I said it's also possible that there are damaged pad or they are just not making contact.

I have a multimeter and I will try testing the resistance... okay, so I tried it on the back of a pcb that still had the layer 1-4 LED's built in and I got a resistance of 2- 2.5 ohms, but this still did not light up the LED.  I cannot get any resistance measurement on these loose LED's, so it's possible they are not working.  I'll check out one of these LED testers on Ebay, if it's inexpensive I don't mind. 

[tp4tissue]

Yes, I'm sure that they are all in the same direction.  There was once or twice that I forgot to disconnect the usb cord and touched a switch contact with the iron.  Maybe I overloaded a few of the LED's.  As I said it's also possible that there are damaged pad or they are just not making contact.

I have a multimeter and I will try testing the resistance... okay, so I tried it on the back of a pcb that still had the layer 1-4 LED's built in and I got a resistance of 2- 2.5 ohms, but this still did not light up the LED.  I cannot get any resistance measurement on these loose LED's, so it's possible they are not working.  I'll check out one of these LED testers on Ebay, if it's inexpensive I don't mind. 

does ur multimeter has that beep setting.

THe Led might just need more power.

are they disconnected? or on the board.

[jcoffin1981]

So I found a battery that powers the LED's.  It's a large button battery, a CR2032 and it's very commonly used in remotes, timers, and other digital devices.  Just slide it in between the two contacts and it works immediately.  Too bad I already ordered an LED tester, but I only paid a few dollar for it. 

I'm drifting off topic, but here's a curious question; does anybody know where I can find a list for the LED controls for the newest firmware of the Poker 3?  I updated it to stop the humming of the lights and I accidentally found more controls.  You can press FN + left Ctrl and there is setting where the light scrolls back and forth across the key rows.  There may be more functions I'm not aware of, but I cannot find these instructions anywhere.  I only see that you can press Fn + X and you can control the brightness or make the lights slowly flash.  I don't think this LED version is being made anymore, so this is hard to find.