Backlight on but no display

Hi, I’m working on a build with my son, we managed to get the backlight on after step 12 (and some solder re-work) but nothing else: no text displayed, and no sound from speaker either. Potentiometer for the backlight works fine, for what it’s worth.

We went ahead and did additional steps to try the reset with button C, but that didn’t help either.

Images included for our soldering; I also checked the CPU and it seems to be seated pretty well.

Any tips appreciated!

Images are from earlier steps before we finished the full build, but finishing it all didn’t improve anything.

We also doublechecked the transistor and voltage regulator orientation/soldering and those seemed ok too

Well we realized that we had not soldered all the pins on the SD card(!)… That was an initial step so we just didn’t realize it until we read another post.

However, now after we soldered those, now we get no backlight at all :frowning:

Here is an updated pic, sorry for the spam!!

I can’t say you the real reason but you have a problem with your solders. They ae round and it’s not good, it’s probably because you don’t put the iron between card and what you have to solde. But then the electrical liaison isn’t good.
i suggest you to have a look at Adafruit’s video tutorial featuring Collin Cunningham – a tutorial featuring Collin Cunningham, a super charismatic electronics guru
Adafruit’s standard soldering tutorial – A great and thorough video tutorial. An absolute must-read, even if you know how to solder. Make sure to check the “common soldering mistakes” section at the end.
Sprakfun’s video soldering tutorial – Another well made how-to-solder video tutorial.
Sparkfun’s standard soldering tutorial – Well written tutorial made by Sparkfun. Then redo bad solders and try again. Its will be easiest after to see if thee is a problem. At the moment, you can’t know if the solder maker contact or not.

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@isu89, thank you for supporting MAKERbuino and welcome to the forum.
as @Jean-Charles_Lebeau already said, you definitely need to improve your soldering joints.

You are putting way too much solder on your soldering joints. More importantly - there must be NO soldering bridges (the soldering joints must not be connected together with solder or the device will not work).

Please take a look at a couple of examples of good soldering joints that I’m sending your right now and also go back to chapter #3 of the build guide (https://www.makerbuino.com/build-3/) and watch a couple of soldering tutorial videos.

Improve your joints a bit and return to us with a few photos.



Thank you for your patience and understanding!
Don’t give up!