Arduino Nano USB-C clone (CH340) not in sync - unable to upload

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1

Hello,

I bought an Arduino Nano clone with USB-C connector from Shopee (imported from China). The board is recognized by Windows as "USB-SERIAL CH340 (COM3)" and the LED L blinks normally, but I cannot upload any sketch.

Error I get:

Warning: attempt 1 of 10: not in sync: resp=0x00
Error: programmer is not responding
Error: unable to open port COM3 for programmer arduino

What I already tried:

  • Installed CH340, CH341 and CH9102 drivers
  • Tried Arduino IDE 1.8.19 and 2.x
  • Tried ATmega328P and ATmega328P (Old Bootloader)
  • Tried pressing reset button during upload
  • Tried double reset trick
  • Tried MiniCore board package
  • Only RX LED blinks very faintly during upload, TX never blinks

Board details:

  • Arduino Nano clone with USB-C
  • Windows 10
  • Recognized as CH340 on COM3
  • LED L blinks every 2 seconds (bootloader seems present)

Any help is appreciated!Use esta tag para formatar o código para o fórum

2

Hi! Welcome to the Forum.

Some things to try:

  1. Make sure your board has an ATMega 328P chip;
  2. Make sure you have closed the Serial Monitor and the Serial Plotter;
  3. If you have something connected to pins 0 or 1 (Rx and Tx), disconnect it before uploading.
3

Hi! Thank you for the response.

1-Yes, the chip is ATmega328P - I can confirm this on the board.

IMG_20260627_211658034_HDR_AE
IMG_20260627_211658034_HDR_AE1920×2560 1.06 MB

2-Serial Monitor and Serial Plotter are closed during upload.
3-Nothing is connected to pins 0 (RX) or 1 (TX) - the board has no connections at all, I am trying to upload with only the USB cable connected.

Additional info: During upload, only the RX LED blinks very faintly. The TX LED never blinks.
I also tried uploading using PlatformIO extension on VS Code, and in that case the response code changed every attempt (0x00, 0x2a, 0xd6, 0x1e, 0xc2). On Arduino IDE the
error is always "not in sync: resp=0x00".

Could this be a bootloader issue specific to this USB-C clone?

4

Probably not.

Unfortunately, that sounds like a defective board.
Some pins have solder marks. What was connected to the board before?

image
image351×316 56.9 KB

5

Can you also post a clear photo of the bottom, please.

There are clones that use rejected / fake CH340 ICs; usually recognisable by the fact that there is no print on the CH340. If that is the case, UNO stopped working after having worked for years - #24 by ptillisch might provide a solution.

When you press and release the reset button, do you get a single flash of the L-LED or a couple of flashes in quick succession? I'm not talking about the blink sketch which flashes the LED one second on, one second off.
A single flash indicates that the board has the old bootloader and you need to select that under Tools → Processor in the IDE; most clones have the old bootloader.

6

Ah yes, I had soldered some wires before that went to an OLED display, but I ended up removing them.

7

When I press and release the reset button, the L-LED stops blinking and then resumes blinking once per second. There is no quick flash sequence - it just returns to the normal 1 second blink pattern immediately after releasing reset.
When I hold the reset button, the L-LED stays off completely. It only resumes blinking when I release the button.
Regarding selecting the old bootloader in the tools, I've already tried that and it didn't work.

Here is a photo of the bottom part.

IMG_20260627_223740905_HDR_AE
IMG_20260627_223740905_HDR_AE1920×1440 640 KB

8

That would indicate that there is no bootloader. You can (try to) burn one if you have a programmer or another 5V Arduino (e.g. Uno).

9

Thank you so much for your help! I'll try to find someone who has an Arduino to lend me. Thanks again for your help and attention.