USB + Serial Backpack Kit + 20x4 RGB LCD

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charlies1
 
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USB + Serial Backpack Kit + 20x4 RGB LCD

Post by charlies1 »

Hello,

I recently purchased and assembled the USB + Serial Backpack kit, however instead of the 16x2 RGB LCD that it came with, I attempted to solder the kit up to my preferred Adafruit 20x4 RGB LCD (PID 498).

I get a red PWR LED lit on the back both when testing over TTL using the example sketch on my Arduino, or via mini USB from my comp.

Here's the problem - I can see the text (faintly), but I get no backlight colors. Everything seems soldered up fine, other than that I made the dumb mistake of trimming off the ends of the headers thinking that they'd only get in the way. Now I realize this will make de-soldering and re-soldering more of a pain....=/

Anyway, I don't know why I am not getting any colors. It is possible the 20x4 LCD is not supported by the Backpack kit?

I can post photos if needed, please advise, thank you!

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adafruit_support_bill
 
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Re: USB + Serial Backpack Kit + 20x4 RGB LCD

Post by adafruit_support_bill »

Do you get any backlight at all? Please post photos showing all your soldering.

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charlies1
 
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Re: USB + Serial Backpack Kit + 20x4 RGB LCD

Post by charlies1 »

Image

Image

Image

As you can see I'm not the best at soldering, but I did make sure that no leads were touching...can you spot anything else that might be wrong?

And to answer your question, no, the screen remains black. But, I can still make out the letters somehow, if I look at the screen at the right angle...

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Franklin97355
 
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Re: USB + Serial Backpack Kit + 20x4 RGB LCD

Post by Franklin97355 »

This might help on the soldering Soldering Guide Two things, make sure your iron is at the correct temp for the solder you are using and use good solder of the right diameter.

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charlies1
 
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Re: USB + Serial Backpack Kit + 20x4 RGB LCD

Post by charlies1 »

What diameter do you recommend?

Also, is there anything else I should possibly check other than looking into re-soldering the backpack?

Is there anyway I can test that the backpack itself isn't fried or damaged?

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Franklin97355
 
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Re: USB + Serial Backpack Kit + 20x4 RGB LCD

Post by Franklin97355 »

This is a good choice I think re-soldering will be your best bet because some of those connections look like they aren't making good contact. You dont need to remove any pins just reheat and remove some of the excess solder.

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adafruit_support_bill
 
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Re: USB + Serial Backpack Kit + 20x4 RGB LCD

Post by adafruit_support_bill »

Many of those appear to be 'cold' joints. And as Franklin says, they will not make reliable contact. This page has some good tips on identifying and correcting common soldering problems. http://learn.adafruit.com/adafruit-guid ... n-problems

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