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geekhack Community => Keyboards => Topic started by: Zackfoo on Sun, 23 October 2016, 07:41:02

Title: Help! Weird led condition!
Post by: Zackfoo on Sun, 23 October 2016, 07:41:02
(http://uploads.tapatalk-cdn.com/20161023/c0d29fc04f580da7d333eaf0ced09789.jpg)

This is a pok3r keyboard. Added led and this happen. Polarity is check which is correct and also led is working I check that too. Anyone can let me know how to fix this?

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Title: Re: Help! Weird led condition!
Post by: Moistgun on Sun, 23 October 2016, 07:52:37
Can you take a picture of the back side of the pcb and post that?

Try for better quality, or a bunch of closer and steadier pics.
Title: Re: Help! Weird led condition!
Post by: Zackfoo on Sun, 23 October 2016, 08:06:41
Can you take a picture of the back side of the pcb and post that?

Try for better quality, or a bunch of closer and steadier pics.
(http://uploads.tapatalk-cdn.com/20161023/346dabf01dceafae3037d9cf25372ba0.jpg)
(http://uploads.tapatalk-cdn.com/20161023/53b74a7d1d5bbc67bd9890d45cc650d1.jpg)
(http://uploads.tapatalk-cdn.com/20161023/f3914b314c8d40cb49c8ea6010d1c2a8.jpg)

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Title: Re: Help! Weird led condition!
Post by: Zackfoo on Sun, 23 October 2016, 08:07:45
First picture is the one with 4 leds that does not light up

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Title: Re: Help! Weird led condition!
Post by: Moistgun on Mon, 24 October 2016, 00:10:12
have you tried to reflow the solder on those four leds?

weird that it would be those in a row though.
Title: Re: Help! Weird led condition!
Post by: Zackfoo on Mon, 24 October 2016, 00:11:57
have you tried to reflow the solder on those four leds?

weird that it would be those in a row though.
I did testing without solder on all switch before installing. It light up normally if I force the pin the touch the wall. Only those 4 does not work even so.

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Title: Re: Help! Weird led condition!
Post by: tp4tissue on Mon, 24 October 2016, 00:50:25
have you tried to reflow the solder on those four leds?

weird that it would be those in a row though.
I did testing without solder on all switch before installing. It light up normally if I force the pin the touch the wall. Only those 4 does not work even so.

Sent from my SM-G935F using Tapatalk



Use the resistance setting on ur multimeter, do the leds light up (at all)
Title: Re: Help! Weird led condition!
Post by: Zackfoo on Mon, 24 October 2016, 02:33:56
have you tried to reflow the solder on those four leds?

weird that it would be those in a row though.
I did testing without solder on all switch before installing. It light up normally if I force the pin the touch the wall. Only those 4 does not work even so.

Sent from my SM-G935F using Tapatalk



Use the resistance setting on ur multimeter, do the leds light up (at all)
Do not have multi meter. But it does can I put again at other on pin holes

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Title: Re: Help! Weird led condition!
Post by: tp4tissue on Mon, 24 October 2016, 12:34:45
have you tried to reflow the solder on those four leds?

weird that it would be those in a row though.
I did testing without solder on all switch before installing. It light up normally if I force the pin the touch the wall. Only those 4 does not work even so.

Sent from my SM-G935F using Tapatalk



Use the resistance setting on ur multimeter, do the leds light up (at all)
Do not have multi meter. But it does can I put again at other on pin holes

Sent from my SM-G935F using Tapatalk



take a double-a battery, or triple-a,  doesn't matter,   tape 2 copper wires to the battery, 

LEDs have polarity, so it only lights up in one direction,   try both directions.. 
Title: Re: Help! Weird led condition!
Post by: cribbit on Mon, 24 October 2016, 13:23:37
It's really hard to diagnose these without a multimeter to check that all the connections are working properly.
Title: Re: Help! Weird led condition!
Post by: Data on Mon, 24 October 2016, 14:18:10
Do you have a coin cell battery?

You can wedge one between the legs on the LED to verify that it works and to check polarity.  Most coin cells don't supply enough current to blow an LED but more than enough to energize it.  I use a CR1632 at home to check all my LEDs.
Title: Re: Help! Weird led condition!
Post by: tp4tissue on Mon, 24 October 2016, 14:25:57
Do you have a coin cell battery?

You can wedge one between the legs on the LED to verify that it works and to check polarity.  Most coin cells don't supply enough current to blow an LED but more than enough to energize it.  I use a CR1632 at home to check all my LEDs.

what;s wrong with a double a.. hahahaha
Title: Re: Help! Weird led condition!
Post by: xondat on Mon, 24 October 2016, 14:27:43
Do you have a coin cell battery?

You can wedge one between the legs on the LED to verify that it works and to check polarity.  Most coin cells don't supply enough current to blow an LED but more than enough to energize it.  I use a CR1632 at home to check all my LEDs.

what;s wrong with a double a.. hahahaha
Try and fit the two ends of an AA in between the legs of a LED
Title: Re: Help! Weird led condition!
Post by: Data on Mon, 24 October 2016, 14:33:00
Do you have a coin cell battery?

You can wedge one between the legs on the LED to verify that it works and to check polarity.  Most coin cells don't supply enough current to blow an LED but more than enough to energize it.  I use a CR1632 at home to check all my LEDs.

what;s wrong with a double a.. hahahaha
Try and fit the two ends of an AA in between the legs of a LED

Winner winner.

And you can do this even after it's soldered.  The angle is a little tricky but it works.
Title: Re: Help! Weird led condition!
Post by: tp4tissue on Mon, 24 October 2016, 14:33:19
Do you have a coin cell battery?

You can wedge one between the legs on the LED to verify that it works and to check polarity.  Most coin cells don't supply enough current to blow an LED but more than enough to energize it.  I use a CR1632 at home to check all my LEDs.

what;s wrong with a double a.. hahahaha
Try and fit the two ends of an AA in between the legs of a LED

AA with 2 wires + tape.. (http://www.cute-factor.com/images/smilies/onion/069.gif)
Title: Re: Help! Weird led condition!
Post by: Data on Mon, 24 October 2016, 14:35:31
Do you have a coin cell battery?

You can wedge one between the legs on the LED to verify that it works and to check polarity.  Most coin cells don't supply enough current to blow an LED but more than enough to energize it.  I use a CR1632 at home to check all my LEDs.

what;s wrong with a double a.. hahahaha
Try and fit the two ends of an AA in between the legs of a LED

AA with 2 wires + tape..
Show Image
(http://www.cute-factor.com/images/smilies/onion/069.gif)


Wires?  Tape?  Now you're just getting fancy.
Title: Re: Help! Weird led condition!
Post by: Zackfoo on Mon, 24 October 2016, 15:02:37
Leds is working. Some other folks just suggest me to route some wires from another led holes. They says that it should be trace problem. That's sad...  But at least it is going to work I don't mind haha. Thx guys for your help! Appreciate it.

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Title: Re: Help! Weird led condition!
Post by: tp4tissue on Mon, 24 October 2016, 22:16:50
Leds is working. Some other folks just suggest me to route some wires from another led holes. They says that it should be trace problem. That's sad...  But at least it is going to work I don't mind haha. Thx guys for your help! Appreciate it.

Sent from my SM-G935F using Tapatalk



yea double check how the resistors are wired..  don't want to jumper cable at the wrong spots.