Troubleshooting LCD RGB Shield

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adafruit_newbie
 
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Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

My LCD RGB shield was working correctly (running HelloWorld and other scripts that I wrote), when suddenly the LCD stopped lighting up when the USB was plugged into the computer. I haven't changed anything since it was originally working. The only change that happens when I plug the Arduino + LCD shield into the computer, is that a row of 16 rectangles divided into 6x8 small squares appears. Has anyone encountered this problem and fixed it?
Thanks

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adafruit_support_mike
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit_support_mike »

Could you post a photo of your hardware please?

adafruit_newbie
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

My hardware:
Attachments
lcd_3.jpg
lcd_3.jpg (71.33 KiB) Viewed 236 times
lcd_2.jpg
lcd_2.jpg (40.5 KiB) Viewed 236 times
lcd_1.jpg
lcd_1.jpg (59.16 KiB) Viewed 236 times

adafruit_newbie
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

The last photo is what I see when I plug in the Arduino via the USB
Attachments
lcd_5.jpg
lcd_5.jpg (57.13 KiB) Viewed 236 times
lcd_4.jpg
lcd_4.jpg (56.77 KiB) Viewed 236 times

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adafruit2
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit2 »

Hi there, when you run the example demo program does the backlight blink on & off?

adafruit_newbie
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

No it doesn`t. The backlight hasn`t come on since last week, when the shield worked perfectly. I haven`t done anything to it since then, so I`m confused about why it suddenly isn`t working.

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adafruit2
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit2 »

Can you try running this program and pasting the output?

Code: Select all

/**
 * I2CScanner.pde -- I2C bus scanner for Arduino
 *
 * 2009, Tod E. Kurt, http://todbot.com/blog/
 *
 */

#include "Wire.h"
extern "C" { 
#include "utility/twi.h"  // from Wire library, so we can do bus scanning
}

byte start_address = 0;
byte end_address = 127;

// standard Arduino setup()
void setup()
{
    Wire.begin();

    while (!Serial);

    Serial.begin(9600);
    Serial.println("\nI2CScanner ready!");

    Serial.print("starting scanning of I2C bus from ");
    Serial.print(start_address,DEC);
    Serial.print(" to ");
    Serial.print(end_address,DEC);
    Serial.println("...");

    // start the scan, will call "scanFunc()" on result from each address
    //scanI2CBus( start_address, end_address, scanFunc );
    uint8_t data;
    for (uint8_t addr = start_address; addr<=end_address; addr++) {
      Serial.print("addr: 0x");
      Serial.print(addr,HEX);
      if (! twi_writeTo(addr, &data, 0, 1, 1)) {
        Serial.print(": found!");
      } else {
        Serial.print("\t");
      }
      Serial.print( (addr%4 == 3) ? "\n":"\t");
  
    }
    Serial.println("\ndone");
}

// standard Arduino loop()
void loop() 
{
    // Nothing to do here, so we'll just blink the built-in LED
    digitalWrite(13,HIGH);
    delay(300);
    digitalWrite(13,LOW);
    delay(300);
}

adafruit_newbie
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

The screen is still unchanged, and this is the serial output:

I2CScanner ready!
starting scanning of I2C bus from 0 to 127...
addr: 0x0 addr: 0x1 addr: 0x2 addr: 0x3
addr: 0x4 addr: 0x5 addr: 0x6 addr: 0x7
addr: 0x8 addr: 0x9 addr: 0xA addr: 0xB
addr: 0xC addr: 0xD addr: 0xE addr: 0xF
addr: 0x10 addr: 0x11 addr: 0x12 addr: 0x13
addr: 0x14 addr: 0x15 addr: 0x16 addr: 0x17
addr: 0x18 addr: 0x19 addr: 0x1A addr: 0x1B
addr: 0x1C addr: 0x1D addr: 0x1E addr: 0x1F
addr: 0x20 addr: 0x21 addr: 0x22 addr: 0x23
addr: 0x24 addr: 0x25 addr: 0x26 addr: 0x27
addr: 0x28 addr: 0x29 addr: 0x2A addr: 0x2B
addr: 0x2C addr: 0x2D addr: 0x2E addr: 0x2F
addr: 0x30 addr: 0x31 addr: 0x32 addr: 0x33
addr: 0x34 addr: 0x35 addr: 0x36 addr: 0x37
addr: 0x38 addr: 0x39 addr: 0x3A addr: 0x3B
addr: 0x3C addr: 0x3D addr: 0x3E addr: 0x3F
addr: 0x40 addr: 0x41 addr: 0x42 addr: 0x43
addr: 0x44 addr: 0x45 addr: 0x46 addr: 0x47
addr: 0x48 addr: 0x49 addr: 0x4A addr: 0x4B
addr: 0x4C addr: 0x4D addr: 0x4E addr: 0x4F
addr: 0x50 addr: 0x51 addr: 0x52 addr: 0x53
addr: 0x54 addr: 0x55 addr: 0x56 addr: 0x57
addr: 0x58 addr: 0x59 addr: 0x5A addr: 0x5B
addr: 0x5C addr: 0x5D addr: 0x5E addr: 0x5F
addr: 0x60 addr: 0x61 addr: 0x62 addr: 0x63
addr: 0x64 addr: 0x65 addr: 0x66 addr: 0x67
addr: 0x68 addr: 0x69 addr: 0x6A addr: 0x6B
addr: 0x6C addr: 0x6D addr: 0x6E addr: 0x6F
addr: 0x70 addr: 0x71 addr: 0x72 addr: 0x73
addr: 0x74 addr: 0x75 addr: 0x76 addr: 0x77
addr: 0x78 addr: 0x79 addr: 0x7A addr: 0x7B
addr: 0x7C addr: 0x7D addr: 0x7E addr: 0x7F

done

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adafruit2
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit2 »

It can't find the MCP23xx driver chip on the shield. The LCD itself is probably fine. It could be arduino is damaged or SCL/SDA pins are not making contact somehow (maybe soldering issue?)

adafruit_newbie
 
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Re: Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

The driver chip is visible in the attached photo (lower right hand side). I have just switched out Arduinos and am experiencing the same problem...do you think a soldering issue could arise suddenly after 6 months of functionality? I will check for connectivity between soldered connections with a multimeter!
Attachments
lcd_1.jpg
lcd_1.jpg (59.16 KiB) Viewed 230 times

adafruit_newbie
 
Posts: 12
Joined: Mon Jul 14, 2014 12:43 pm

Re: Troubleshooting LCD RGB Shield

Post by adafruit_newbie »

The driver chip is visible in the attached photo (lower right hand side). I have just switched out Arduinos and am experiencing the same problem...do you think a soldering issue could arise suddenly after 6 months of functionality? I will check for connectivity between soldered connections with a multimeter!

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Franklin97355
 
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Re: Troubleshooting LCD RGB Shield

Post by Franklin97355 »

Some of the solder joints on there look a bit weak take a look at this Soldering Guide That might help.

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