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Topic: Can I find out if this display is boken ? (Read 151 times) previous topic - next topic

jfri

I have purchased this display module
https://www.banggood.com/7-Inch-800-x-480-TFT-Touch-LCD-Display-Module-MCU-Bus-CPLD-SDRAM-p-916216.html?rmmds=myorder

I use it with a  a CTE TFT LCD/Sd Shield for Arduino Due with a Due card. It has worked before. But know it remains dead (i.e black display) when using the same example code that has worked before.

My question is if and how could confirm that I actually has a piece of broken hardware ?

One suspicion is that it might have broke when I connected the display to the shield. The number of connector pins on the display is two less than on the connector header on the shield. So it can be connected in two ways (two pair of header pins can be empty). It is possible that I by mistake can have connected the display incorrect. If so would the result be that the display will be damaged in such a way that it remains black ?
I have tried with two different Due modules. I have connected a real time clock to it which worked.

david_prentice

Surely the display has a 20x2 male header.   The CTE Due Adapter has a 20x2 female socket.
Every female is happy.   Every male is satisfied.

It looks as if the display requires VCC = 3.3V
The Adapter probably has a jumper or solder-bridge to select 3.3V or 5V for VCC.

Note that clone "CTE" Adapters made by Sainsmart are generally supplied with the wrong settings.

I do not own a big 7" display.   The backlight takes a LOT of current.

David.

jfri

Surely the display has a 20x2 male header.   The CTE Due Adapter has a 20x2 female socket.
Every female is happy.   Every male is satisfied.

It looks as if the display requires VCC = 3.3V
The Adapter probably has a jumper or solder-bridge to select 3.3V or 5V for VCC.

Note that clone "CTE" Adapters made by Sainsmart are generally supplied with the wrong settings.

I do not own a big 7" display.   The backlight takes a LOT of current.

David.
For sure the display has 19*2 pins and in addition to that two not used holes marked NC NC  so on the board place for a 20*2 header but only 2*19 used. The CTE adapter has indeed a 20*2 female socket of which only 19*2 can be used by the display module and that can be done in two ways.

I have not made any changes to the jumpers and if they were wrong the display shouldn't have from the beginning which it did.
The display do indeed require a lot of power so in addition to the USB cable I also connect a DC adapter that can output 18 VA. Without it the demo example didn't work correctly although it did not rendered the display
completely black.

david_prentice

You have the display in front of you.   I can't see how many pins from the BangGood photos.

But 20x2 is the normal pinout for this style of display.   i.e. it mates with the 40-pin female socket on the CTE Adapter Shield.   It is "obvious" how to plug it into the Adapter.

No, you must read the documentation carefully.   If the display needs 3.3V,  you should configure the settings properly.    If the Adapter was made by CTE,  it will be good quality.   But you still need to configure properly.

If it was made by Sainsmart,  you must check for solder-bridges, missing components, bad joints. ... and definitely for bad VCC settings.

You have a very expensive display.  It is worth being careful.

David.

GlennHarber


jfri

Any pictures of this one?
I don't see how I can upload a picture. Insert image asks for a URL not a file on my computer.

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