LCD problem

Hi guys,
I just finished building my first Shruthi, lot of fun!. I will order another soon. But before.
When building tests, the LCD was OK i calibrated it. After putting all this in the case, the LCD is really pale even if i turn the trimmer. IT’s like there is not enough voltage?
The machine seems to work but i can barely see what is on the screen
I have a 9V DC 1000mA unregulated PSU testing 13,31 volts.
A picture
Somebody can help?

Did you use the 3.3 ohm resistor that came with the kit instead of the 68 ohm?

If the LCD was OK until you built everything into the case and all the rest still is, I suspect the soldering of the connection between the digital control board and the LCD may be the culprit. Can you closely check the connections (both sides of the 16x1 connector) and maybe resolder them?

Sorry but i’m new to that, at what step of the building procedure it was? I used what was in the kit :slight_smile:

Had same problem and one via was defective. Solder joint was on one side and track on other, so the track had no connection with joint. It was a track between Atmega and LCD. I recommend to check connections between Atmega and LCD with multimeter.
I connected missing connetion with wire.

are you asking pichenettes or bytefrenzy?
if it’s the resistor, it’s R20 in Step 1 (resistor number 1) in the manual, on the pic upper right.
if you’re asking about the lcd-> board connection, it’s the 6 pin header that connects the lcd to the digital board. try to reheat the individual joints one after another and maybe apply a little bit solder. if it doesn’t work you can try the other side of the connector too (on the digital board)

ByteFrenzy want you check the STEP12 of the procedure , when you solder the 16x1 connector : on PCB and LCD

Thanks a lot guys, i will check all those cues tonight and will give you some news.
Mark, the green guy in building electronics…:slight_smile:

Hi guys,
Missing a solder on the lcd connection control board side .Yes! LCD working
Thanks a lot.

Yahoo! The machine is running! Sounds as I wanted.
“I’m the operator of my pocket calculator…”

:wink: congrats!