i2c 16x2 lcd not working

hey guys, 
I am running in to some issues trying to get my LCD display up and running. 
I am using this Display, and get only a blank output : https://www.az-delivery.de/products/lcd-...bAEALw_wcB

The connection between the pi and the lcd seems to be working. I used a clean install of Debian lite and followed this tutorial, and got the lcd to work: https://medium.com/@thedyslexiccoder/how...9a0760ae15. 
I guess it would have to be a configuration issue. 

I have enabled USE_I2C_LCD = 16x2 (also tried =True)
also changed the I2C_LCD_ADDR=0x27 (because I have the PCF8574(T), also tried 0x3f, no luck)

I also tried a clean fresh install, without success. 
I am a bit lost and out of things to try. maybe some one has a solution ?

best regards, 
Lorenz

Hi Lorentz,
Hardware issues can be hard to find.
If you're lucky, you might see messages during manual startup.
Some help on how to debug is on Commandline access and debugging (chapter on "How to build" page).
I also saw a related forum topic
Hope this helps,
Noek

Hey Noek, thank you for you reply and your suggestion. 
The solution from the other topic you suggested, sadly doesn’t work for me, I didn’t change any backlight options. 
I couldn’t see anything during startup, that would relate to my problem. 
Regarding debugging, I am far from an expert. The thing that i tried was to check the i2c connection to the display with i2c tools, which showed me a connection on port 27. 

I don’t know wether I am missing something, but I would rule out a hardware problem (meaning physical connection or fault of the display or raspberry pi hardware)  because it works, with the exact setup, just a different software. I would guess it has to be a configuration issue of some sort 

Maybe someone has a clue what’s going on, or some concrete trouble shooting steps? 
I would greatly appreciate your help

[quote pid="530" dateline="1708990406"]
Hey Noek, thank you for you reply and your suggestion. 
The solution from the other topic you suggested, sadly doesn’t work for me, I didn’t change any backlight options. 
I couldn’t see anything during startup, that would relate to my problem. 
Regarding debugging, I am far from an expert. The thing that i tried was to check the i2c connection to the display with i2c tools, which showed me a connection on port 27. 

I don’t know wether I am missing something, but I would rule out a hardware problem (meaning physical connection or fault of the display or raspberry pi hardware)  because it works, with the exact setup, just a different software. I would guess it has to be a configuration issue of some sort 

Maybe someone has a clue what’s going on, or some concrete trouble shooting steps? 
I would greatly appreciate your help
[/quote]

I had this problem too, begin to check if config file is OK with I2C display that you are using, check the adress match the one that IC tools gave you.
Then check the connection to pins in the PI are correct.
If nothing helps, for me what solved it was to format again the SD card, aparently, a faulty installation will give this issue.
Also, there's a screw in the back that regulates the contrast of the LCD screen. Try that.