Blocks on LCD  


John McGrath
Active Member
Joined:11 months  ago
Posts: 5
March 26, 2017 11:12 am  

I stepped away from the project for a while after getting the Arduino to work.

Just powered it back up, and all its showing is blocks on the LCD.  

I have another Arduino that I can try, but I am loath to replace it if it is not broken.


New Member
Joined:8 months  ago
Posts: 2
April 7, 2017 7:03 pm  

Have you tried it with the PC interface? If it works with that it is more likely to be the display.

Active Member
Joined:11 months  ago
Posts: 10
April 8, 2017 4:32 pm  


I posted this comment elsewhere on the forum a few weeks ago. It might help.  My display was bright blocks until I replaced the fixed resistors with the pot that came with my display.  

My other issue was related to the LCD.  After waiting exactly 1 month to get the DealsExtreme delivery from China for the LCD, Arduino, and DDS, I found the LCD had a serial board soldered to all the pin pads.  Rather than try to desolder it, I ordered one without the board via Amazon Prime and had it in 2 days.  It cost $5.99 rather than $2.39 but was worth it.  When I installed and fired it up the display had nothing but bright blocks. I hooked it to an o'scope and made sure the Arduino was talking.  I then  desoldered the fixed resistors (a little more trouble since they are under the LCD board) and installed the multi-turn 10K pot that came with the LCD. After a few turns of the pot, the display became readable.  The LCD literature said it uses LED rather than electroluminescent illumination which may have caused the problem.  




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