ESP32-S3 with RGB LCD only works when IDE is active

[fitterman]

I have built a project that consists of the Metro ESP32-S3 board, a proto shield with some temperature sensors and pullup resistors and the Adafruit RGB LCD shield. The project has come a long way on the software side and I'm about ready to deploy it. Unfortunately, while it works great with the IDE active, it fails with a stand-alone power source. Instead of operating, the shield shows Line 0 fully of black blocks and Line 1 is blank. You can see photos of what this looks like as well as a photo of the shield when it works.

Here is what I've tried: (1) an external 9V 1.5A power supply through the barrel connector, (2) a standalone 5V 3A power supply through the USB-C connector and (3) connecting it through my Mac using the USB-c connector. The first two fail. The last one fails if the IDE is not active and everything works perfectly when the IDE is active. I've also tried removing the proto shield and that has no change in the observed behavior.

I'm a software guy and I'm a little uncertain with how to diagnose this further. Following one suggestion, I put a 10kohm resistor between RST and 3.3V, which didn't change anything. I've tried searching for similar reports and come up empty. Any ideas? Please try to be as explicit as you can as I don't know a ton about the hardware side and would really appreciate some patient guidance. Thanks!

[Timeline]

Perhaps the same solution as this discussion?
viewtopic.php?p=1044341

[fitterman]

I wanted to expand on my question. Is there anything about the shield that I should be aware of in terms of pins to inspect for bad soldering or other issues that might account for this behavior. Even when I remove the intermediate perfboard with the temperature sensors, the problems shows. In other words, it's 2 Adafruit products and they don't work together, so I'm wondering about my soldering, etc. I'm attaching including 2 more photos in case there's a particular pin that you think might be relevant with regard to my amateur soldering job.

[Timeline]

Yes the soldering can definitely be improved. I am seeing what to me look like cold solder joints such as these...

ColdSolderCapture.PNG (265.6 KiB) Viewed 16 times

Cold solder joint tend to form when you don't properly heat up both the pin and the pad and the solder only flows on the hot one and beads up against the cold one but not making a good connection. In the picture it looks like you heated the pins but didn't have the solder tip also touching the pad.

Do you have any flux by any chance? Often the easiest way to fix these is apply a good amount of flux and simply reheat the joint allowing the existing solder you have on there to reflow onto the pad as well. Talking about something like this https://www.adafruit.com/product/3468

[T_Mo]

(only a community member)
All those joints could use some flux and reflow.