Answer these questions
To fully understand your problem with the ESP32 DevKit V1 (38-pin) brownout message during Wi-Fi scanning, I need to ask a series of questions to clarify all relevant details:
What is the exact brownout message or output you see on the serial monitor? Please provide the full text if possible.
Are you using any specific code or example sketch to perform the Wi-Fi scan? If so, can you share the code you are running?
What is the power source for your ESP32 when you encounter the brownout? Is it powered only through the USB cable from your PC or through an external power supply as well?
Has anything changed in your setup since it last worked correctly (e.g., different USB cable, different computer USB port, added peripheral devices, etc.)?
What is your development environment? For example, are you using Arduino IDE, ESP-IDF, or another environment? What version?
Are you using any external components connected to the ESP32 now or was it completely standalone as you mentioned?
Can you describe the USB cable and connection quality? For example, newer or older cable, data vs. power-only cable, USB port type (USB 2.0, 3.0), etc.?
Have you measured the 3.3V power rail voltage on the ESP32 when the brownout happens or seen any voltage dips?
Are you aware of any recent updates or changes to your ESP32 board firmware, bootloader, or libraries that might coincide with this issue?
Do you see the brownout only during Wi-Fi scanning or also under other higher power load conditions (e.g., during Wi-Fi connection, using Bluetooth, or heavy processing)?
Please provide as much detail as you can on these points. Once I have a complete picture of your current setup, environment, and behavior, I will summarize the main details and then provide a tailored recommendation to resolve the brownout during Wi-Fi scanning.
What details can you provide first?