Serial connection problem and connection to server failed
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Dear all,
After unpacking the M5STAMP PICO (D4), I immediately installed the latest firmware. I then soldered it directly to a PCB. However, the blue LED remains lit during startup.
The current meter on my lab power supply repeatedly jumps back and forth (approximately 50~100mA): apparently, it is repeatedly trying to connect. The Wi-Fi mode (yellow) is working properly: I can connect to configure the Wi-Fi key.
I unsoldered GPIO pins G0 through G3 to reinstall the firmware. This doesn't work. "A serial connection cannot be established."
This problem resembles https://forum.m5stack.com/topic/7606/m5stamp-pico-solid-blue-light
However, soldering seems to be the problem here
(of course, I checked for bad connections or short circuits to pins or to components near the pads).What could I try to fix the problem? Where should I look?
Thank you in advance.