How to check LCD module?

check lcd module

I used to connect pin1(Gnd) of LCD to Vcc and pin2(Vcc) to Gnd once.
now this LCD cannot use, it's contrast is very pale so I don't sure LCD can display every position (I think maybe some position cannot display). I don't know how to check and repair. I think capacitor is'n work now & I try to use 0.1uF instead the old two C. I think it's better a little but contrast is the same. Anyone know how to check or information page please tell me. thank you very much

working with pc1602

Hi,
Reversing the supply voltage can damage not only capacitors, but also some onboard electronics used for bias voltage generation. Sorry for common answer, but you should be more specific with LCD type etc.

hai,


what type of lcd and do u used?/
which controller???

hi
I use Text LCD 16*2 and controller is HD44780.
thank you

Try short pin3 to ground (in series with 1k resistor for safty), see if contrast improved.

I dont know if you have opportunity , but if you have you can use a simple circuit with 16F84 PIC and a simple code written in picbasic

' PicBasic program to demonstrate operation of an LCD in 4-bit mode
'
' LCD should be connected as follows:
' LCD PIC
' DB4 PortA.0
' DB5 PortA.1
' DB6 PortA.2
' DB7 PortA.3
' RS PortA.4 (add 4.7K pullup resistor to 5 volts)
' E PortB.3
' RW Ground
' Vdd 5 volts
' Vss Ground
' Vo 20K potentiometer (or ground)
' DB0-3 No connect

Pause 500 ' Wait for LCD to startup

loop: Lcdout $fe, 1 ' Clear LCD screen
Lcdout "Hello" ' Display Hello
Pause 500 ' Wait .5 second

Lcdout $fe, 1 ' Clear LCD screen
Lcdout "World"
Pause 500 ' Wait .5 second

Goto loop ' Do it forever

first, get the data sheet of lcd then follow the datasheet if it's hard to follow, just search the same series of lcd

Hi,

I have a similar problem except I didn't reverse voltage. I made LC meter and tried to use used Powertip PC1602-F1 (2*16) LCD. This LCD show me nothing after switching power on. In manufacturer's datasheee't I found nothing special. I change this LCD to another manufacturer's one and it working. Could I try to connect negative voltage to PC1602 module? Could it damadge LCD if not supported?

Regards,
Saulius

try to connect to any microcontroller you have, and run program for initializing LCD the final code is command for deleting character on display and RAM.
if your LCD is working then all display will show blank, if it's not working check your connecting cabble especially the bus connector and data connector.
mostly the LCD are not stong if you placing wrong polarity supply and could damage the LCD. :wink:

hi, saulius
try to check yor connecting cabble, ihave the same experience with you and the problem on the cabble that i used to connect to LCD