How to Fix the dim LCD backlight or not showing an image

Post by **Helder** » Sat Jul 22, 2017 5:10 pm

So I ran into the same issue some people had with the LCD turning on where the back light was very dim then no image showed. I tested voltage and it was 2.5v where it needed to be 3.3v and it ended up being a bad Ground on the 8pin connector on the PCB. If you have this issue a simple fix is to link the 2nd pin to the GND pad below the connector like the image below.

Orangebuster · Post by **Orangebuster** » Sat Jul 22, 2017 6:38 pm

Thanks for this solution Helder. I was having this issue and I linked the second pin to ground, but nothing still shows up on the screen

EDIT: okay, so it had something to do with the ribbon cable being in juuuuusst right.

Robochris · Post by **Robochris** » Sat Jul 22, 2017 6:57 pm

Maybe off topic but is there a test pad for the gpio pin labeled "D/C"?

Orangebuster · Post by **Orangebuster** » Sat Jul 22, 2017 7:12 pm

Yeah it's in the middle of the line of test pads, next to rst and sdi

Robochris · Post by **Robochris** » Sat Jul 22, 2017 7:16 pm

Oh shit. Thanks.

L51 · Post by **L51** » Mon Jul 24, 2017 1:58 am

I am also having this problem. I just solder some wire to join the pin correct?

Post by **Helder** » Mon Jul 24, 2017 2:55 am

Yes just like the image on the first post.

abrugsch · Post by **abrugsch** » Mon Jul 24, 2017 3:43 am

Is that bad ground likely to be on the prototype board I have?
Cheers

Post by **Helder** » Mon Jul 24, 2017 5:55 am

No that one has some changes made around that area from the final version. I looked at the board files and the gnd there shouldn't have had an issue but little faults are bound to happen in a large production run. I'm just glad it happened to me so I could document it and the fix.

L51 · Post by **L51** » Tue Jul 25, 2017 5:04 am

Will there be a second revision where the screen works straight outta the box because mine going in the bin

How to Fix the dim LCD backlight or not showing an image

How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

Re: How to Fix the dim LCD backlight or not showing an image

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