So my I2C adapter and LCD display were working very nicely up until now when something happened and the LCD is showing a row of black boxes on the first line and no characters are displayed. I tried to run the HD4478 - I2Cexpdiag sketch and apparently, this is what happened:
I2CexpDiag - i2c LCD i/o expander backpack diagnostic tool
hd44780 lib version: 1.1.0
Reported Arduino Revision: 1.8.9
CPU ARCH: AVR - F_CPU: 16000000
SDA digital pin: 18 A4
SCL digital pin: 19 A5
Checking for required external I2C pull-up on SDA - YES Checking for required external I2C pull-up on SCL - NO Checking for I2C pins shorted together - Not Shorted
WARNING: I2C requires external pullups for proper operation It may appear to work without them, but may be unreliable and slower Do not be surprised if it fails to work correctly Install external pullup resistors to ensure proper I2C operation
Scanning i2c bus for devices..
Does this mean the SCL pin is damaged? and if so, is there a way I can fix this or I should just buy a new one instead? I dont think its a pull-up resistor problem since the arduino uno has pull-up resistors itself and my LCD was working normally previously.