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2.2" TFT LCD Screen Has Defective Pixel Patch
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2.2" TFT LCD Screen Has Defective Pixel Patch

by engnatha on Mon Feb 11, 2019 8:25 pm

Hi,

I opened my recently purchased TFT display today for the first time and noticed that it had a defective patch in one of the corners where the pixels seem to glow brighter than the others. I have attached a picture to show this better. Communication with the board works fine over SPI with an NodeMCU v1.0 ESP-12E module.

One weird thing was that I could only get the system to work with CS disconnected. This is fine as I only have one SPI device on the bus, but connecting CS would not allow the ESP-12E to boot even though I had it configured properly per the optimized ESP library I was using for this: https://github.com/Bodmer/TFT_eSPI.

Thanks
Attachments
badScreen.jpg
badScreen.jpg (86.92 KiB) Viewed 144 times

engnatha
 
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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by adafruit_support_carter on Mon Feb 18, 2019 1:56 pm

The CS pin behavior seems odd. Can you post another photo with better lighting that shows how everything is connected and the solder job on the TFT display headers.

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by engnatha on Mon Feb 18, 2019 3:37 pm

I have attached the requested picture. I am using a nodeMCU board so the pin mapping is coming directly from the User_setup.h requirement from the TFT_espi library that is available. Pin mapping is as follows:
BL - N/C
SCK - D5
MISO - D6
MOSI - D7
CS - GND
SDCS - N/S
RST - D4
D/C - D3
VIN - 5v0
GND - GND

For testing, I have tried with MISO connected/disconnected, SDCS pulled up/down, and BL connected to 5v0 with each case having all other pins as defined above. Only thing that has worked is when CS is pulled directly to GND. I reworked all the header pins to be safe and pin D8 on my nodeMCU since it was not great. Pin resistances between CS and all others are as follows:
BL - 214.6 K
SCK - 283 K
MISO - 277.9 K
MOSI - 283.6 K
SDCS - 11.71 K
RST - 13.88 K
D/C - 13.92 K
VIN - 10.01 K
GND - 11.65 K
Attachments
20190218_135846.jpg
20190218_135846.jpg (129.15 KiB) Viewed 118 times
20190218_135816.jpg
20190218_135816.jpg (164.97 KiB) Viewed 118 times

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by adafruit_support_carter on Mon Feb 18, 2019 5:21 pm

Do you have an Arduino board available for testing so we can use a known working configuration?
https://learn.adafruit.com/2-2-tft-display

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by engnatha on Mon Feb 18, 2019 5:34 pm

I do have one, but I would like to not have to rework my setup for this testing. I also believe it will not resolve my original issue of having the defective pixel coloring in the corner.

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by adafruit_support_carter on Mon Feb 18, 2019 8:36 pm

It looks like some form of physical damage. Like maybe it was damaged in shipping. Can you get any image at all to show? Or just the white screen?

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by engnatha on Mon Feb 18, 2019 8:50 pm

All aspects of the screen are working fine other than the CS pin issue that I mentioned. I have been able to develop my project fine with the discolored pixels but would like the final product to not have this issue.

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by adafruit_support_carter on Mon Feb 18, 2019 10:41 pm

Is it possible it's just the protective cover? Something on it?

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by engnatha on Mon Feb 18, 2019 10:44 pm

No, I forgot to mention that was one of the things I checked. I pulled up the cover and it was still discolored due to the screen. I've left the cover on until I'm done with my development.

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by adafruit_support_carter on Mon Feb 18, 2019 10:52 pm

OK. Let's replace it. It seems damaged in more ways than one. The screen thing seems like shipping damage. The CS thing may or may not be related.

Send an email to support@adafruit.com with a link to this thread and your order number and they can send you a replacement TFT display.

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by engnatha on Tue Feb 19, 2019 10:41 am

Okay, how should I proceed on that? I would like to keep developing my project and not have the logistics of returning/replacing eat up that time.

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Re: 2.2" TFT LCD Screen Has Defective Pixel Patch

by adafruit_support_carter on Tue Feb 19, 2019 1:41 pm

Send an email to support@adafruit.com with a link to this thread and your order number and they can send you a replacement TFT display.

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Please be positive and constructive with your questions and comments.