Avrdude: ser_open(): can't open device "\\.\COM5": acces denied

Development Tools Uploading
1

I use an arduino nano, with the ATmega328P (oldbootloader), and IDE version 1.8.19.
whwn I try to upload my scetch, even if I try to upload something fairly simple, Ive tried 2 different Nanos, the same thing happnes every time, I checked device manager, if I unplug my nano, COM5 disaperas and when I replug it, it appearsb again, if I restart my pc sometimes it lets me upload a scetch but only one time, even if I dont unplug the board it wont let me upload a scetch a second time. With the same setting I was able to use this board a few day ago, and before Ive tried to upload a new scetch Ive tried the board and the old program was running flawlessly.

2

Please disable Show verbose output during compilation and enable Show verbose output during upload under file → preferences in the IDE.
Perform an upload and post the full result here; don't forget code tags (the <CODE/> button).

3 
avrdude: Version 6.3-20190619
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "C:\Users\Felhasznalo\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/etc/avrdude.conf"

         Using Port                    : COM5
         Using Programmer              : arduino
         Overriding Baud Rate          : 57600
avrdude: ser_open(): can't open device "\\.\COM5": A hozz�f�r�s megtagadva.



avrdude done.  Thank you.

Problem uploading to board.  See https://support.arduino.cc/hc/en-us/sections/360003198300 for suggestions.

A hozz�f�r�s megtagadva. (this part means: acces denied)

4

I should also have asked what the serial-to-usb converter on the board is. It's the chip on the bottom of your board; does it have text written on it? If not sure, take a clear picture and post it here.

"Access denied" might indicate that another process is using the serial port. You can check that by installing Process Explorer.

Instructions for usage: Exit error status 1 on Arduino uno - #15 by ptillisch and Exit error status 1 on Arduino uno - #18 by sterretje.

5

20250226_171620
20250226_1716201848×4000 493 KB

Okay, you, I don1t see any writing on that, but here is the bottom of the board.

6

image
image495×266 4.26 KB

Process explorer doesnt give me any results

7

OK, based on the pin count it's a CH340.

Which driver version does Windows device manager report. If it had 2024 in the version, you can try to roll back the driver. Instructions e.g. here: Port monitor error: command 'open' failed: Invalid serial port. Could not connect to COM serial port - #49 by ptillisch.

Note
Those unmarked ICs are possibly rejected dies and a 3rd party buys them and packages them.

8

@gabor99
There is a smd transistor on the board , normaly not there.

Is the prosessor 328P or 328PB?

9

It is 328P

10

I had similar problems with Nano's 328BP and the unmarked USB chip.

MiniCore solved that after I updated the Bootloader.
There is a lot of video's that will explain the "How to.."

https://www.youtube.com/watch?v=eeQJDV_e1Vg

11

Thank you verry much it solved the probelm