# Cannot connect and upload code to NodeMCU

**URL:** <https://forum.arduino.cc/t/cannot-connect-and-upload-code-to-nodemcu/1343960>\
**Category:** Uploading\
**Created:** [January 18, 2025, 3:47am UTC](https://forum.arduino.cc/t/cannot-connect-and-upload-code-to-nodemcu/1343960 "2025-01-18T03:47:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![chiragp09](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/chiragp09/32/1126741_2.png) [@chiragp09](https://forum.arduino.cc/u/chiragp09)\
**Post date:** [January 18, 2025, 3:47am UTC](https://forum.arduino.cc/t/cannot-connect-and-upload-code-to-nodemcu/1343960/1 "2025-01-18T03:47:45Z")

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I have tried using 5 different USB cables, I have used Arduino version 1.8.19, then updated to 2.3.4. Also tried ESP8266 version 3.0.0 then updated to 3.1.2. Nothing seems to fix the problem.

Variables and constants in RAM (global, static), used 28104 / 80192 bytes (35%)  
║ SEGMENT BYTES DESCRIPTION  
╠══ DATA 1496 initialized variables  
╠══ RODATA 920 constants  
╚══ BSS 25688 zeroed variables  
. Instruction RAM (IRAM\_ATTR, ICACHE\_RAM\_ATTR), used 59667 / 65536 bytes (91%)  
║ SEGMENT BYTES DESCRIPTION  
╠══ ICACHE 32768 reserved space for flash instruction cache  
╚══ IRAM 26899 code in IRAM  
. Code in flash (default, ICACHE\_FLASH\_ATTR), used 232148 / 1048576 bytes (22%)  
║ SEGMENT BYTES DESCRIPTION  
╚══ IROM 232148 code in flash  
esptool.py v3.0  
Serial port COM5  
Connecting...  
A fatal esptool.py error occurred: Write timeout

I am currently getting this error on Arduino IDE version 2.3.4, ESP8266 version 3.1.2.  
How do i fix it.

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<div class="post-metadata">

**Author:** ![MaximoEsfuerzo](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/maximoesfuerzo/32/923798_2.png) [@MaximoEsfuerzo](https://forum.arduino.cc/u/MaximoEsfuerzo)\
**Post date:** [January 18, 2025, 4:50am UTC](https://forum.arduino.cc/t/cannot-connect-and-upload-code-to-nodemcu/1343960/2 "2025-01-18T04:50:02Z")

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Press and hold the `FLASH` button when the console show "connecting..."  
Or try with a 1uF to 10uF capacitor between `RST` and `GND` pins.

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**Author:** ![chiragp09](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/chiragp09/32/1126741_2.png) [@chiragp09](https://forum.arduino.cc/u/chiragp09)\
**Post date:** [January 18, 2025, 5:04am UTC](https://forum.arduino.cc/t/cannot-connect-and-upload-code-to-nodemcu/1343960/3 "2025-01-18T05:04:14Z")

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Hey, I tried holding the flash button, it didn't do anything.  
Also i don't have a capacitor available with me right now. I just want to make sure the board lights blink so I know that the board works.

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**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [July 17, 2025, 5:04am UTC](https://forum.arduino.cc/t/cannot-connect-and-upload-code-to-nodemcu/1343960/4 "2025-07-17T05:04:25Z")

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Closed on July 17, 2025, 5:04am UTC

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