V2 IDE wont program to a Mega 1280

[softfoot]

I have installed the V2 ide under WIN10 and for most boards it works fine but I cannot program a MEGA1280 - it reports "access denied" on com40.
I can program a MEGA2560 or an UNO OK
A terminal program is able to connect OK.
I am able to program it using a USBasp - but the production boards dont have an ISP connector.
V1 of the IDE under WIN7 works just fine.
I have to move away from V1 of the ide.
Dave

[per1234]

Thanks for your report @softfoot. Please tell us which USB to serial bridge chip your Arduino board has. This is a black chip near the USB socket.

The chip will usually be identified by writing on the top. This might say something like "WCH CH340G" or "FTDI FT232RL".

Examples:

WCH CH340

📷

SparkFun - CC BY-SA 4.0 (cropped)

There are some boards on the market that have a USB chip with the same IC package as the WCH CH340, and which are identified by the computer as a CH340. However, these chips don't have the "WCH CH340C ..." labeling like you see on the chip in the picture above:

📷

NodeMCU Lua Lol1n V3.jpg by Popolon - CC BY-SA 4.0 (cropped)

These mysterious unlabeled chips have different characteristics than the labeled CH340 chips, so please let us know if yours is labeled or not.

Silicon Labs CP2102

📷

SparkFun - CC BY-SA 4.0 (cropped)

FTDI FT232R

📷

ICIC-SS28-X-K232-01 by oomlout - CC BY-SA 2.0 (cropped)

---

If it isn't clear, alternatively you can provide the link to where you bought the board from and we'll see if we can determine the chip from the product listing.

[softfoot]

The chip is definitely a FTDI  FT232RL and my usb tools confirm it as such. The thing is that the uart is perfectly useable once programmed (you cannot reprogram it via USB but the program is able to use it OK) And the v1 IDE CAN program it reliably via USB. Could it be a problem with v2 IDE resetting the chip?? Dave

…

On 20/12/2025 20:17, Per Tillisch wrote: *per1234* left a comment (arduino/arduino-ide#2837) <#2837 (comment)> Thanks for your report @softfoot <https://github.com/softfoot>. Please tell us which USB to serial bridge chip your Arduino board has. This is a black chip near the USB socket. The chip will usually be identified by writing on the top. This might say something like "*WCH CH340G*" or "*FTDI FT232RL*". Examples: WCH CH340 <http://www.wch-ic.com/products/CH340.html> CH340.jpg (view on web) <https://github.com/user-attachments/assets/8c67242d-c59a-45fb-bc9b-0d817a1fba7f> _📷 SparkFun <https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers/all> - CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0/> (cropped) There are some boards on the market that have a USB chip with the same IC package as the WCH CH340, and which are identified by the computer as a CH340. However, these chips don't have the "WCH CH340C ..." labeling like you see on the chip in the picture above: unlabeled-SOIC-16.jpg (view on web) <https://github.com/user-attachments/assets/50277b35-2c7c-4d89-acd0-b967a21d940e> _📷 NodeMCU Lua Lol1n V3.jpg <https://commons.wikimedia.org/wiki/File:NodeMCU_Lua_Lol1n_V3.jpg> by Popolon <https://commons.wikimedia.org/wiki/User:Popolon> - CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0/> (cropped) These mysterious unlabeled chips have different characteristics than the labeled CH340 chips, so please let us know if yours is labeled or not. Silicon Labs CP2102 <https://www.silabs.com/interface/usb-bridges/classic/device.cp2102> CP2102.jpg (view on web) <https://github.com/user-attachments/assets/c7dfa282-10d2-4441-8026-ec141e3797ca> _📷 SparkFun <https://learn.sparkfun.com/tutorials/cp2102-usb-to-serial-converter-hook-up-guide/all> - CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0/> (cropped) FTDI FT232R <https://ftdichip.com/products/ft232rl/> image.png (view on web) <https://github.com/user-attachments/assets/6e3c6e74-b0cf-43ef-918e-f5485eba9859> _📷 ICIC-SS28-X-K232-01 <https://www.flickr.com/photos/snazzyguy/15800423994/> by oomlout <https://www.flickr.com/people/snazzyguy> - CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0/> (cropped) ------------------------------------------------------------------------ If it isn't clear, alternatively you can provide the link to where you bought the board from and we'll see if we can determine the chip from the product listing. — Reply to this email directly, view it on GitHub <#2837 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACE2J2CYU4BW76MB64D3XCD4CWVF5AVCNFSM6AAAAACPUMUEQSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMNZYGA4DIOBXG4>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[per1234]

Thanks for the clarification.

I see we have another report about this at #1783.

It is best to have only a single issue per subject so we can consolidate all relevant discussion to one place, so I'll go ahead and close this in favor of the other.

Please note the workaround that is provided in the other issue:

#1783 (comment)

[softfoot]

I tried the suggested fix - it MADE NO DIFFERENCE so please reopen it !! I note that that fix was for V1 IDE - I have the problem on V2 --- the board works perfectly under V1 IDE Dave

…

On 21/12/2025 10:56, Per Tillisch wrote: *per1234* left a comment (arduino/arduino-ide#2837) <#2837 (comment)> Thanks for the clarification. I see we have another report about this at #1783 <#1783>. It is best to have only a single issue per subject so we can consolidate all relevant discussion to one place, so I'll go ahead and close this in favor of the other. Please note the workaround that is provided in the other issue: #1783 (comment) <#1783 (comment)> — Reply to this email directly, view it on GitHub <#2837 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACE2J2BS4I6WAEGSYKFF2HD4CZ4GVAVCNFSM6AAAAACPUMUEQSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMNZYGY4DOOJXGY>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[per1234]

I tried the suggested fix - it MADE NO DIFFERENCE

I'm sorry to hear that. Please request assistance over on Arduino Forum:

https://forum.arduino.cc/c/development-tools/ide-2-x/93

I'm sure we'll be able to help you find a solution over there. I closely monitor Arduino Forum, so I'll be sure to see your topic over there.

please reopen it !!

I'm certain the problem you are experiencing is #1783. There is no benefit to having two issues open for the same bug.

Please note that this issue tracker is only a place for the developers to track bugs. It is not a place for users to obtain support. Arduino Forum is the dedicated place for support requests.

I note that that fix was for V1 IDE

That is incorrect. The fix is for Arduino IDE 2.x. I have personally verified it works perfectly on Arduino IDE 2.3.7.

The fact that you somehow got the impression that it was for 1.x makes me think that maybe you didn't correctly follow the instructions. I recommend trying again, this time making sure to read them carefully and follow them precisely.