Soldering SMD LEDs onboard CF 5.1

[mikestar007]

Is it necessary to use sold wire to link the ground to holes 1-7? Also is it crucial to have an SMD resistor ,or could a well placed 1ohm 1/4 watt normal resistor be used?

Also people that have done this before, any tips or tricks you would like to share please do!

[CHEWBACCA]

Yes to first question...no to second.  I have never used resistors when soldering SMD LEDs on the board itself.

For a tip search erv's site for a video on soldering the resistors  on (I "think" he has one).

Those pads are actually for a 0402 footprint but those are harder to solder for some and 0603 will work

[mikestar007]

Yes to first question...no to second.  I have never used resistors when soldering SMD LEDs on the board itself.

For a tip search erv's site for a video on soldering the resistors  on (I "think" he has one).

Those pads are actually for a 0402 footprint but those are harder to solder for some and 0603 will work

Thanks! I have watched his video on SMD soldering ,very helpful.

So solid wire is a must, is that what is on the ends of resistors ?

[CHEWBACCA]

Sorry I must have misunderstood you question.  You can use braided wire (should always use braided wire on the rest of the saber) as long as you solder all the grounds together and to the ground pad. 

I just completely tin a piece of braided wire most of the time since I have it on hand.  For connecting the negatives solid will work though (yes the leads on regular resistors are solid and can be used).

Yes to first question...no to second.  I have never used resistors when soldering SMD LEDs on the board itself.

For a tip search erv's site for a video on soldering the resistors  on (I "think" he has one).

Those pads are actually for a 0402 footprint but those are harder to solder for some and 0603 will work

Thanks! I have watched his video on SMD soldering ,very helpful.

So solid wire is a must, is that what is on the ends of resistors ?

[mikestar007]

Sorry I must have misunderstood you question.  You can use braided wire (should always use braided wire on the rest of the saber) as long as you solder all the grounds together and to the ground pad. 

I just completely tin a piece of braided wire most of the time since I have it on hand.  For connecting the negatives solid will work though (yes the leads on regular resistors are solid and can be used).

Yes to first question...no to second.  I have never used resistors when soldering SMD LEDs on the board itself.

For a tip search erv's site for a video on soldering the resistors  on (I "think" he has one).

Those pads are actually for a 0402 footprint but those are harder to solder for some and 0603 will work

Thanks! I have watched his video on SMD soldering ,very helpful.

So solid wire is a must, is that what is on the ends of resistors ?

1.Ok glad I can use pretined braided wire. So I connect the pretined wire from the ground negative to the 7 holes. But where exactly does the resistor go?

2.Also that's definate no on useing a regular resistor? my led is rated for 3.2v and 20ma. I feel like I almost don't need one lol.

[CHEWBACCA]

Correct...that is what I mentioned in my previous post.  I never use a resistor when soldering SMD LEDs onto the board.  If you wanted to you could put a resistor between the gnd wire and ground itself.



also Sorry I accidentally hit modify instead of quote when responding to you...that is why your post says it was modified by me.

[mikestar007]

Correct...that is what I mentioned in my previous post.  I never use a resistor when soldering SMD LEDs onto the board.  If you wanted to you could put a resistor between the gnd wire and ground itself.



also Sorry I accidentally hit modify instead of quote when responding to you...that is why your post says it was modified by me.

Thanks for your help. I got them soldered up. But I when to test it and they don't light up. fairly sure I made good connections. (Im saving led 1 for the crystal)

[1000moths]

I can't properly see from that pic but it doesn't look like you've soldered the joined negative pads to the single ground (the one marked GND next to the switch pads)

[CHEWBACCA]

You may have the  LEDs backwards. Also here is a tip.  Solder he ground wire on the bottom for a much cleaner look. 

1000moths he has it to the ground in the middle of the accent LEDs which that version of CF has.

Correct...that is what I mentioned in my previous post.  I never use a resistor when soldering SMD LEDs onto the board.  If you wanted to you could put a resistor between the gnd wire and ground itself.



also Sorry I accidentally hit modify instead of quote when responding to you...that is why your post says it was modified by me.

Thanks for your help. I got them soldered up. But I when to test it and they don't light up. fairly sure I made good connections. (Im saving led 1 for the crystal)

[mikestar007]

Got it working ! So it turns out I soldered them on backward every one. It was because the battery I tested them with had two red wires  :P stupid. Reversed them and solder then back on.

But my new question I bought these leds a long time ago so I have no data sheet. But when I tested them they lit up green. But now that they are on the board they are Yellow.

No idea the forward voltage any guesses?

[1000moths]

1000moths he has it to the ground in the middle of the accent LEDs which that version of CF has.

Ah, I should have spotted it was a prior version, thanks Chewie!

I'm about to do the same on my 7.5, the only real bummer is the LEDs sit right on a part of the hilt that's threaded so a bit nervous about cutting in to make them visible!

[QUI-GON JINN]

Got it working ! So it turns out I soldered them on backward every one. It was because the battery I tested them with had two red wires  :P stupid. Reversed them and solder then back on.

But my new question I bought these leds a long time ago so I have no data sheet. But when I tested them they lit up green. But now that they are on the board they are Yellow.

No idea the forward voltage any guesses?

If they are supposed to be green,  and are lighting up yellow,  it is very likely they are being over driven.

[mikestar007]

Got it working ! So it turns out I soldered them on backward every one. It was because the battery I tested them with had two red wires  :P stupid. Reversed them and solder then back on.

But my new question I bought these leds a long time ago so I have no data sheet. But when I tested them they lit up green. But now that they are on the board they are Yellow.

No idea the forward voltage any guesses?

If they are supposed to be green,  and are lighting up yellow,  it is very likely they are being over driven.

Wow I've never heard of them changing  colors being overdriven ,it must just be a 10th of a volt.
Would you know how likely they are to pop overdriven .1 volt?

[QUI-GON JINN]

No, I'm not sure if they'll burn out or not, but I've had that happen to me before with 3mm and 5mm green led's so it's possible that's what happening here.

Got it working ! So it turns out I soldered them on backward every one. It was because the battery I tested them with had two red wires  :P stupid. Reversed them and solder then back on.

But my new question I bought these leds a long time ago so I have no data sheet. But when I tested them they lit up green. But now that they are on the board they are Yellow.

No idea the forward voltage any guesses?

Not sure how you know it's only a 10th of a volt,  since you said you don't know the forward voltage it could be more than that. I looked at some smd's on an electronics site,  and saw several that only had a vf of 2.2v, and a few that only needed 5-10ma.  You need to find the specs on what you have,  or get some new ones that are rated for around 3.3v and 20ma.

[mikestar007]

No, I'm not sure if they'll burn out or not, but I've had that happen to me before with 3mm and 5mm green led's so it's possible that's what happening here.

Got it working ! So it turns out I soldered them on backward every one. It was because the battery I tested them with had two red wires  :P stupid. Reversed them and solder then back on.

But my new question I bought these leds a long time ago so I have no data sheet. But when I tested them they lit up green. But now that they are on the board they are Yellow.

No idea the forward voltage any guesses?

Not sure how you know it's only a 10th of a volt,  since you said you don't know the forward voltage it could be more than that. I looked at some smd's on an electronics site,  and saw several that only had a vf of 2.2v, and a few that only needed 5-10ma.  You need to find the specs on what you have,  or get some new ones that are rated for around 3.3v and 20ma.

I assumed it was 3.2v since most greens I saw online were that voltage. But right was was I thinking soldering up the leds without know exactly what the are rated for. :-\