ESP32 Forum

Hello, I made my own PCB with ESP32-S3-Mini-1U-N8. I have an issue that it doesn't show up on my PC nor my laptop, i checked with two normal cables and one with swapped data pins. I've already made two PCBs with S3-mini, the only difference from the working ones and this one is that it's a 4 layer board and the gpio assignments changed.

I already checked:

• 3.3V gets to the 3.3V pin on the ESP32
• GPIO0 is at 3.3V, goes to 0V when pressing Boot button
• EN pin is at 3.3V, also goes to 0V on press
• GPIO45 and GPIO46 are pulled down.

I don't know what could cause this since the microcontoller, chip boot control and button sections were copied from the schematic of a working pcb.

After some thought I came up with a possibility that I burned the chip. For the first assembly I decided to desolder ESP32 from a PCB that got destroyed (the esp worked fine), I used default 350C hot air station temperature for quite some time since I had to heat up the chip take it off, then solder it on the new board with a hot plate set to 215C. Then it didn't work, so i took it off and hot air soldered a new one with the same 350C setting. I swapped this chip before and it still works, but is it possible that I ended up damaging both esp32?

TLDR: I don't know what causes ESP to not work, is it possible to damage the board by heating it up for too long while hot air soldering?

Can you still reach U0TXD? Might be useful to see if there's any serial debug info emitted on that pin.

I never thought about including test points or pins for uart but it could be useful in future projects.

I could try getting a small wire or a probe on the TX pad, thank you for that idea.

Case closed. I didn't get any signal on TX pin so I surely damaged it during soldering. I assembled a new board and it works fine.