ESP8266 Community Forum

- Sun Mar 06, 2016 6:55 am #42542 Hi,

I was using a recently arrived ESP-07 module and connected it to a minimal programming circuit:

USB 3.3V TTL converter with 5V output

lv33cv LDO (fed from 5V output of TTL module) with decoupling capacitors

VCC and CH_PD of ESP-07 connected to 3.3V output of LDO, GND connected to common ground of LDO and USB module

used a switch to connect RST to ground while pressed

used a switch to connect GPIO0 to ground while pressed, 10k resistor as pullup

connected GPIO 15 to GND

After I connected the USB module the red LED of the ESP-07 went on and the blue one started flashing. I hold the reset button, pressed the firmware button (GPIO0 to GND) and release reset. Unfortunately esptool did not recognize an ESP8266 module. I accidentally touched the LDO, which was really hot, and directly removed it from my computer.

I rechecked if the LDO was oriented properly - it was. Then I used a regulated power supply which includes a current limitator. I only connected VCC and GND, and the power directly went through the ceiling (> 0.3A). The red and blue LEDs didn't flash anymore. I measured ~ 2 Ohm between VCC and GND.

The module now seems pretty dead. Do you have any idea what the problem might be? Did I make any mistake. I programmed an ESP-01 module with the same LDO and USB TTL module some days ago without any problem.

Thanks in advance

- Wed Mar 23, 2016 5:58 pm #43903 I had a similar issue with ESP-07. It wasn't a new device and had been used outdoors for almost a year. I removed the can and discovered that current draw is really high (300mA) and ESP and regulator are really hot. Furthermore, ESP is working fine, but pulling CH_PD low does not reduce current draw. Could be oscillator circuit or some other passive component which is failing. It could be static discharge or general failure from corrosion. I'll find out.