Positive 16x2 RGB LCD not working, no backlight

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

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adafruit_support_bill
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by adafruit_support_bill »

To view the board files, you need the Eaglecad package. It is a free download.
http://www.cadsoftusa.com/download-eagle/freeware/

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wallykissel
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by wallykissel »

Never mind. Downloaded 'EAGLE' to read the schematics.

tnagy14
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by tnagy14 »

I believe I have traced the problem down to a short somewhere between the SDA and SCL pins. The only active component connected to those pins is the IC. I am planning to buy one from digikey and try it out. In the mean time, is it possible to exchange the LCD with the missing capacitor. Note that I bought this kit through Maker Shed so does it need to be returned to them?
Thanks,

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adafruit_support_bill
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by adafruit_support_bill »

We can replace the display for you. Contact [email protected] with a link to this thread and request a replacement RGB LCD for your shield.

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wallykissel
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by wallykissel »

wallykissel wrote:
wallykissel wrote:
adafruit_support wrote:@tnagy - The schematics and board files are all here: https://github.com/adafruit/Adafruit-RGB-LCD-shield
btw: What processor are you connecting this to?

@wallykissel - It sounds like an i2c communication problem. I am not familiar with the Funduino, but we have seen problems with some of the clones. If you post photos of the front & back of the board, we can check your assembly.
Post photos of the back? Sounds like a de-soldering challenge. I will borrow a friends stock UNO tomorrow and try the 'Hello World' demo.

- Wally
I'm open for suggestions on how to view the .brd and .sch files. @ https://github.com/adafruit/Adafruit-RGB-LCD-shield

Downloaded 'Eagle' to see the files.

Looks like my problem is the clone. RGB LCD demo works fine with an R3 UNO.

Thanks,
- Wally

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wallykissel
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by wallykissel »

Found the problem with the I2C communication. Followed the A4 & A5 lines on the LCD shield and the Due many times but never looked back at the ATMega pins. Mystery solved, all is well. (It actually was more like a solder 'splash' as it came loose very easily. None the less, it was shorting the pins.)
Attachments
Solder bridge on ATMega pins
Solder bridge on ATMega pins
solder.jpg (79.13 KiB) Viewed 717 times

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adafruit_support_bill
 
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Re: Positive 16x2 RGB LCD not working, no backlight

Post by adafruit_support_bill »

Good diagnostic work! Thanks for the follow-up.

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