segment on 4 digit 7 segment not displaying

Question

Segment E on digit 3 has stopped working for some reason. It was working fine when I first got but just recently stopped working. This segment displays fine on the other digits except digit 2, that one has started to fade. Here is a picture of the display. Any ideas on what could be causing it to be not working and/or how to fix it.

Answer 1

You have most probably burned the segment in question. The use of only one resistor per digit is the main reason. You need use a resistor for each segment. Furthermore to prevent losing a nex display again use a larger resistor to begin with. With 330 or 390 ohm per segment it will work fine.

With the use of one resistor per digit you can not control the actual segment current and since no diode is equal there will always be one that takes a larger current than the remaining segments. Therefore change over to one resistor per segment.

Answer 2

From the pictures you seem to be using the one-resistor-per-digit approach. When one of the digits or one of the output pins change somewhat this will probably not work well. Try to use one resistor per segment.

Answer 3

Any ideas on what could be causing it to be not working and/or how to fix it.

a device / segment failure is certainly a possibility. However, I have done similar things (using 1 resistor per digit) or worse (no resistors at all) and they work just fine.

the simplest and surest way is to take out the display and put the segments to a power source (with a resistor) to test. if that particular segment doesn't light up, you have found the reason.

after that, I would look into the code first and to make sure that there is nothing funky going on there. try to light up just that segment for example to see if indeed there is a problem.

then, I would go after the wiring. those boards aren't that greatest in securing contacts. maybe the pins are bent, maybe the wires aren't where they are supposed to be, ...

Answer 4

Copy and paste the code shown below, this will help you to:

1. Configure board pin
2. Display pin
3. Error in board pin, display pin or jumper wire by replacing all of components one by one, you can add more pins for other configurations.

Code:

int ledDelay = 1000; 
int pin2 = 2;
int pin3 = 3;
int pin4 = 4;
int pin5 = 5;
int pin6 = 6;
int pin7 = 7;
int pin8 = 8;

void setup()

{

pinMode(pin2, OUTPUT);
pinMode(pin3, OUTPUT);
pinMode(pin4, OUTPUT);
pinMode(pin5, OUTPUT);
pinMode(pin6, OUTPUT);
pinMode(pin7, OUTPUT);
pinMode(pin8, OUTPUT);

}

void loop()

{
digitalWrite(pin2, HIGH); // turn the red light on

delay(ledDelay); // wait 50 ms

digitalWrite(pin3, HIGH); // turn the blue light on

delay(ledDelay); // wait 50 ms

digitalWrite(pin4, HIGH); // turn the blue light on

delay(ledDelay); // wait 50 ms

digitalWrite(pin5, HIGH); // turn the blue light on

delay(ledDelay); // wait 50 ms

digitalWrite(pin6, HIGH); // turn the blue light on

delay(ledDelay); // wait 50 ms

digitalWrite(pin7, HIGH); // turn the blue light on

delay(ledDelay); // wait 50 ms

digitalWrite(pin8, HIGH); // turn the blue light on

delay(ledDelay); // wait 50 ms

return;
}