Author Topic: Help! Weird led condition!  (Read 2913 times)

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Offline Zackfoo

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Help! Weird led condition!
« on: Sun, 23 October 2016, 07:41:02 »


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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Offline Moistgun

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Re: Help! Weird led condition!
« Reply #1 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.

Offline Zackfoo

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Re: Help! Weird led condition!
« Reply #2 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.




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Offline Zackfoo

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Re: Help! Weird led condition!
« Reply #3 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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Offline Moistgun

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Re: Help! Weird led condition!
« Reply #4 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.

Offline Zackfoo

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Re: Help! Weird led condition!
« Reply #5 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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Offline tp4tissue

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Re: Help! Weird led condition!
« Reply #6 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.

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Use the resistance setting on ur multimeter, do the leds light up (at all)

Offline Zackfoo

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Re: Help! Weird led condition!
« Reply #7 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.

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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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Offline tp4tissue

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Re: Help! Weird led condition!
« Reply #8 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.. 

Offline cribbit

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Re: Help! Weird led condition!
« Reply #9 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.
I typed this post on my Slanck. I also developed a stronger, cleaner, easier handwiring method.


Offline Data

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Re: Help! Weird led condition!
« Reply #10 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.

Offline tp4tissue

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Re: Help! Weird led condition!
« Reply #11 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

Offline xondat

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Re: Help! Weird led condition!
« Reply #12 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

Offline Data

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Re: Help! Weird led condition!
« Reply #13 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.
« Last Edit: Mon, 24 October 2016, 14:34:54 by Data »

Offline tp4tissue

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Re: Help! Weird led condition!
« Reply #14 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..

Offline Data

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  • Location: Orlando, FL
Re: Help! Weird led condition!
« Reply #15 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


Wires?  Tape?  Now you're just getting fancy.

Offline Zackfoo

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Re: Help! Weird led condition!
« Reply #16 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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Offline tp4tissue

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Re: Help! Weird led condition!
« Reply #17 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.

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