Some LCD GFX keys stuck

Just got a LCD GFX and got it up and running - except it appears the C and D keys are stuck.
Running the example program (and change the elif’s to if’s so it tests all the keys) the C and D keys keep being pressed. It doesn’t help pressíng them a lot of times. The other keys works as expected - the A key appeared to have been stuck to but that I apparently got unstuck. Also ran the and the snake moved immediately.

Did the Pico you used come with the header pre soldered, or did you solder one on?
Just want to rule out a header issue. If one or more of the pins used by the buttons get shorted to ground, it would be the same as holding the button down.
It’s surprising how many pins are ground on the Pico, it was to me anyway.
Raspberry Pi Pico GPIO Pinout
GFX Pack schematic is here, that shows what pins / GP are used by the buttons.
GFX_pack.sch (

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I soldered them myself, thank you ;-) And I think I’ve done a pretty good job if I may say it myself - even though it is ages since I last did some real soldering - and my version 6.0 eyes are not as good as they used to be incl. my hands. :-D (and yeah I noticed the half finished pin GP14 soldering).

And now I’ve gone through each and every pin to see if there are any shorts - and apart from the ground pins my multimeter kept quiet - but some of the pins only have a resistance of 400-800 ohm between them - but I think that that is as it should be - I’m still looking for some documentation for that - without having to go through the diagrams from pin to pin. :-D
I’ve also used the Pico for another project where quite a few pins were connected to make a resistance ladder to control the X/Y on an oscilloscope which worked quite well - much better than I anticipated - and anything else works when I connect the PIco to the LCD GFX, i.e. all the programs do what I expect them to do - except when it need keyboard input (from key C & D).

Might be a couple that need touching up. Pin 2 looks like it might be a cold solder joint?

I also see some residue or spatter on that side. Might be worth cleaning that off if you have some isopropyl alcohol and an old toothbrush.

On the whole it looks good, I’m just a bit picky when it comes to soldering.
I’m in the same boat. Eyesite isn’t what it used to be, and my hands aren’t all that steady anymore.

Seeing as you have an ohm meter, I’d check the switches on the GFX Pack, without the Pico plugged in. Might have to plug some jumpers in, but it should be doable. I posted a link to the schematic above, that will tell you what pin goes to what button. Or just measure the solder pads on each side of the button. The jumpers will likely be a lot easier, those solder pads are pretty small.

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