u/BiruDoBiruleibe

I just received my first custom PCB and I’m having a really hard time getting the power supply section to work.

The core of the board is an ESP32-C6 powered by a TPS63900 buck-boost converter. The input is currently 5V from a USB port, but the TPS63900 is outputting exactly 0V.

What I’ve tried so far:

• Desoldered the ESP32 to make sure there are no shorts or heavy loads on the 3.3V line.
• Replaced the TPS63900 with a fresh one using a hot air station, just in case the first one was baked or dead on arrival. Still 0V.
• Verified that V_MUX (Input) is getting 4.8V (5V minus a Schottky drop) right at the input cap (C13).
• Checked continuity: EN pin is tied to VIN, so it should be pulled high. SEL1/CFG1/CFG2 are tied to GND. CFG3 has a 16.2k resistor to GND (which should set it to 3.3V.

Any help or ideas on what to probe next would save me, thanks!

I just received my first custom PCB and I’m having a really hard time getting the power supply section to work.

The core of the board is an ESP32-C6 powered by a TPS63900 buck-boost converter. The input is currently 5V from a USB port, but the TPS63900 is outputting exactly 0V.

What I’ve tried so far:

• Desoldered the ESP32 to make sure there are no shorts or heavy loads on the 3.3V line.
• Replaced the TPS63900 with a fresh one using a hot air station, just in case the first one was baked or dead on arrival. Still 0V.
• Verified that V_MUX (Input) is getting 4.8V (5V minus a Schottky drop) right at the input cap (C13).
• Checked continuity: EN pin is tied to VIN, so it should be pulled high. SEL1/CFG1/CFG2 are tied to GND. CFG3 has a 16.2k resistor to GND (which should set it to 3.3V.

Any help or ideas on what to probe next would save me, thanks!

I just received my first custom PCB and I’m having a really hard time getting the power supply section to work.

The core of the board is an ESP32-C6 powered by a TPS63900 buck-boost converter. The input is currently 5V from a USB port, but the TPS63900 is outputting exactly 0V.

What I’ve tried so far:

• Desoldered the ESP32 to make sure there are no shorts or heavy loads on the 3.3V line.
• Replaced the TPS63900 with a fresh one using a hot air station, just in case the first one was baked or dead on arrival. Still 0V.
• Verified that V_MUX (Input) is getting 4.8V (5V minus a Schottky drop) right at the input cap (C13).
• Checked continuity: EN pin is tied to VIN, so it should be pulled high. SEL1/CFG1/CFG2 are tied to GND. CFG3 has a 16.2k resistor to GND (which should set it to 3.3V.

Any help or ideas on what to probe next would save me, thanks!TPS63900 Buck-Boost outputting 0V.