Unable to get LCD to work...

[hawk1943]

Hi there,

I've just etched a new PCB using the attached schematic, but since populating the board the LCD no longer works, yet the code and everything else was working fine on the prototype rig...

I have the PIC 16F877 working as I have RS232 communications, but just unable to get anything to work on the actual LCD...

Does anyone have any sugguestions as to what I can try...

I have attached the source code I am using and Schematic Drawing...

The code is fully tested and worked on the prototype fine before it died on me... hence the reason I had to etch a new PCB...

 

[hawk1943]

OK, I have now stripped out all of the other code, and gone back to a previous working section of code, that basically tests the functionality of the LCD...

But still I am getting nothing on the display...

All pins are wired correctly...

I'm attaching the code I am using to see if anyone can offer some advice...

All that I am seeing on the display is ROW 1 & ROW 3 a series of Black Squares...

RS - RW - ENABLE are all at 0V with DB4 at 5V and DB5, DB6 & DB7 are at 0V...

All suggestions are gladly welcomed...

 

[hawk1943]

Sorry...

For some strange reason I was unable to attach the code to the last message...

So will try again...

 

[john blue]

Most probably you got dry solder, trace short. Try to check the PCB's continuity. Some pins might not be connected properly or some might accidentally get shorted.