Problem with 18x2 adafruit LCD Display turning on

Hello, I am a new user to this forum and am not very tech savvy. I have read all I could from google pointing to this forum and have not found a solution to my problem. I am using an Arduino Uno and have purchased RGB LCD Shield Kit w/ 16x2 Character Display - Only 2 pins used! [POSITIVE DISPLAY] : ID 716 : $23.95 : Adafruit Industries, Unique & fun DIY electronics and kits and am having trouble getting the display to turn on. I have reviewed the steps (Assembly | RGB LCD Shield | Adafruit Learning System) and rechecked my work at least 5 times:

  • The resistors are the correct colors placed in the correct locations (95% sure they all make good connection with the board and are soldered well)

  • I have placed all the pushbuttons in and the potentiometer and have bent them all carefully and tightly to ensure they make connection with the board (I did not solder these though, could that be the problem? Although, I am sure they make contact with the board and are secured well by being bent well)

  • The I2C port chip is placed correctly with the notch facing the proper direction (to the right) and the pins are bent securely and it is making contact with the board

  • I have followed the rest of the process accurately and have multi-checked that any soldering was done well and individually as to not make an unwanted connection and to short the circuit
    Edit: Also, I have the potentiometer currently set to the middle but have tried turning it all the way left and all the way right as well to no avail.

  • When I upload the sketch (have tried example → LiquidCrystal → Blink and the RGB LCD Shield code given by adafruit Arduino Usage | RGB LCD Shield | Adafruit Learning System) it reaches the Done Uploading phase and there are no errors

  • The compiler is set to Arduino Uno, the port is correctly selected, and my computer makes a (connection) noise to properly notify me that the device is read and connected

  • Even if I remove the LCD display and place it back into the 18 pins is makes the noise again to show that it is accepted and connected

I really am at a loss for why the display is not turning on. Any help is and will be greatly appreciated! (again I am new and I hope I did not break any rules for whatever reason, sorry!)

Images: https://postimg.org/gallery/2zm77hsek/

  • For Image 2, the R2 resistor is (indeed) a yellow, violet, red, gold resistor. I had just damaged the yellow coloring from gripping at it too much with a tweezer.
  • Apologies for Image 3 being rotated (sorry for the laziness to not rotate it).

How good is your soldering technique?

Could you pls make a sharp picture of your board (face and bottom side) showing precisely the solder spots and the wiring to your Arduino.

Thank you for your reply! I’m not exactly sure how to rate my soldering technique other than say I am a beginner but I have multi-checked that I didn’t have the solder connect two pins that should not be connected. No solder of one pin was touching another.

I have attached 7 pictures, although focus on pictures 4-7 for close ups I took of my soldering. Thank you for your time!

I am horrified. The soldering of the header pins looks ok.
But the other components are not soldered at all.

View a "how to solder" video. Solder all the components properly.
Crop the leads neatly.

You have bought an LCD to go with the shield. You need to solder this too.

When you have finished, every joint will look as good as factory soldering.
Your shield will work perfectly.

Bending pins is not a reliable way to make an electrical connection.
Ok, many professional cables are "crimped". But this uses special tools and ensures that the metal surfaces are intimately pressed together.

David.

As @david_prentice already pointed out:

This won't ever work!
You need to produce really solid solder spots to make it work.

If possible, get you a punch tape board and some cheap resistors and some tinned wires and learn to solder; only after that you should go on with your Adafruit shield.
Avoid any bended connections. First stick the devices pins through the hole(s), solder them and then cut the wires which are too long, so that about 0.5 - 1.0 mm of the wire is still visible above the solder spot.

Follow @david_prentice advice to study a good video tutorial about soldering, then start with the test board and after you feel a bit more comfortable, go with your shield again. Soldering looks pretty easy, but it is a technique where timing, temperature and a bit of experience is needed -> means you have to learn it to be successful.

Here are some links to video tutorials:

Good afternoon, thank you for all the responses. They are greatly appreciated. Thank you for your suggested advice and videos, I have watched them and tried to apply the techniques to my soldering and I think I did a good job on some of them but I have burned some of them too (unfortunately). I wasn’t able to practice with your suggestion as I tried doing this before I head off to work because I wanted to try to get this working before I started my day but unfortunately it still does not turn on with all the connections soldered.

I have attached images of my soldering and have renamed the images after the focus points of my pictures to show the soldering for that component.

** NOTE: Also, if it matters: I had incorrectly soldered the short header pins to the LCD that came with the kit to the top when it should be the long pins facing up and the short pins facing down. Because of this, I also found an old LCD display I had ordered about 4-5 years ago and have used this instead to correctly solder the long pins facing up. A possible problem is that I had soldered 18 header pins when I just realized the package labels it as a 16x2 but the assembly article says"

“If you already soldered all 18 pins but you have a 16 or 14 pin LCD, simply cut off the right-most pin tops until it fits.”

Given this, I didn’t have a problem with my pins fitting so does it matter that the extra two pins are soldered and connected? If it is a problem I can just desolder it. (If I had more time and didn’t have to go to work I would just test this myself).

Possible problems:

  • Soldered poorly and didn’t make a solid connection (I do not see any solderings connecting to another and causing a short)
  • 16x2 LCD Display has 18 header pins
  • The Liquid Crystal Display basic example code from Arduino IDE needs to be changed in some sort (could this be an issue?)

Again, I greatly appreciate any feedback and advice and look forward to reading this after work. Sorry if any of what I’ve done seem to be extremely silly and nooby mistakes. Have a good day everyone :).

I am sorry to say - if you think you soldered all pins which have to be soldered - NO, you didn't.

There are still a lot of "bended connections" - this won't work!!

  1. You have to solder every single pin which you mounted on the pcb board by fiddling it through the solder hole.
  2. Then I might have seen a burnt solder spot, but could also be because of misleading light on a picture.
  3. I cannot verify if you placed all the devices correctly or turned them by 180 degrees ...
    -> the cheap little buttons have 2 positions to be soldered right and 2 positions to solder them "unconnected" to the circuit of the board.
    -> For resistors it doesn't matter if they are turned, but
    -> for the display pins it does matter.
  4. About the 16pin/18 pin issue - I can't say; for this I have no experience. But you might identify some information on the display / carrier board to see if the right pins match (e.g. if you find Vcc on the display and +5V or Vcc on the carrier they have to match; GND 2 GND, data pin x to data pin x, RS to RS etc.

Thank you for your reply.

In an effort to learn, would you be so kind as to answer:

  • What do you mean by the pushbuttons have 2 positions to be soldered right and 2 positions to be soldered "unconnected"?
  • The pins I have bent are the chip, the pushbuttons, and the potentiometer and then soldered as I originally thought bending them would secure them enough initially at the time of posting this thread. Could you please enlighten me on why bending it would cause errors? Thank you!

Thank you for your time and response, it is helping me learn immensely!

Do you have a cheap multimeter?
If not, I think it's time to get one as this will get you some steps further in electronics.

  • What do you mean by the pushbuttons have 2 positions to be soldered right and 2 positions to be soldered "unconnected"?

When you measure the pins each by each of those buttons, let's call them 1..4 beginning leftmost top and then clockwise, you will notice, that, when you push the button while still measuring, only two positions will show a connection.

Could you please enlighten me on why bending it would cause errors?

Looking at your picture it appears to me as if those pins are only bended and not soldered. If they are soldered, ok, it might work - but based on your picture - at least very bad solder spots and I am not sure that they are really giving good connection to the tracks on the board.

We can go on like this for the next weeks, but I am afraid that your soldering skills still incorporate hidden errors - thus my best advice for the time being is, that you get in touch with an experienced electronics guy locally and have him/her check your board with all devices and the solder spots. If this procedure succeeds, we could concentrate on the software side - if the problem(s) are still present.