Having problem in supplying correct current to LCD

[caramelz]

I'm using TC1602A LCD and PIC18F4520 microchip. the LCD display square black box when I tried to display something. When i connect 5V from the fixed 5v power supply, it can display what I want. Can anyone tell me what wrong with it ? I tried to use potential meter to reduce the current but it burned.

 

[D.A.(Tony)Stewart]

I tried to use potentiometer to reduce the current but it burned.

Somethings sounds miswired or ESD damaged. The Chip takes 10mA and the backlight 250mA and the recommended pot 10K I think is for contrast bias.

So I am not sure what happened.

 

[caramelz]

I connect LCD pin1,2,3 to pot 1,3,2 . Is it correct? is it because the LED background took too much current?

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i'm using a 9V 0.75A Adapter output adapter.