# PROBLEM SOLVED - DEFECTIVE ARDURINO BOARD - I'm stumped. Can't upload any sketches to Uno or Mega, I could 9 years ago **URL:** \ **Category:** Uploading\ **Created:** [May 5, 2026, 6:33am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692 "2026-05-05T06:33:50Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 6:33am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/1 "2026-05-05T06:33:50Z")
THANK YOU ALL - Uno Problem solved - Over the years a component must have failed or a component of trace became corroded or there's a cold solder joint. I was able to find 3 other Arduino Unos I had and they are working perfectly. First think I noticed was when I went to select the port, it showed the Uno was connected. Still having an issue with the Mega. But it's looking like if I upload the same Blink sketch I get an error, but the sketch works as it should. (I'll deal with this later). I was into Arduino about 9 years ago and had to step away. For the past 9 years the two computers with all of my sketches, an Uno and Mega that and the 2 USB cables sat untouched. I'm getting back into Arduino and opened the box thinking I could pickup where I left off. Neither computer has been connected to the Internet, so NO UPDATES. I'm running IDE 1.8.12 When I try and upload a sketch that was working to I'm getting the following error avrdude: stk500\_recv(): programmer is not responding avrdude: stk500\_getsync() attempt 1 of 10: not in sync: resp=0x24 I'm getting this with both computer, both usb cables and the Uno and the Mega. Tried swapping USB cables and Arduinos between the two computers. I have tried another USB cable, and the USB cables I have work with other devices. Verified I'm using the correct board and USB port in IDE. And yes the USB ports are working fine. Tested with a keyboard and mouse. But what's interesting.... Is if I move the Arduino USB cable to a different USB port, IDE sees it. No USB errors in Windows Device Manager. Tried updating the boot loader, but since I can communicate with the Arduinos, I can't. There are no shields on either board. Both Arduinos are still running the code I last uploaded nearly 10 years ago. I have a new (3rd) computer, Windows 10 where I downloaded the current IDE, 2.3.8 and it won't communicate either. Tried another USB cable, didn't work either. I've can't even load something as simple as the the Blink sketch. In every attempt the code complies without errors. I have even gone so far as to install the CH340 driver. Which makes no sense as the software was everything was working perfectly 9 years ago. Any suggestions? Thank you ---
**Author:** ![docdoc](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/docdoc/32/220907_2.png) [@docdoc](https://forum.arduino.cc/u/docdoc)\ **Post date:** [May 5, 2026, 8:52am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/2 "2026-05-05T08:52:26Z")
Unless both boards are damaged, the situation is strange... but first of all: are we talking about original Arduinos or clones? Both? And what IDE settings are you using for the board? Could you post a screenshot of the settings? Also, the only strange thing that drives me crazy is: > [@Doug101](#): > > But what's interesting.... Is if I move the Arduino USB cable to a different USB port, IDE sees it. I believe (hopefully) your PC has been updated frequently over the past 9 years, so it seems the problem lies with something you're using (from the USB drivers to the IDE). Have you tried completely uninstalling and reinstalling the USB-serial drivers (using the latest version)? ---
**Author:** ![sterretje](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sterretje/32/391294_2.png) [@sterretje](https://forum.arduino.cc/u/sterretje)\ **Post date:** [May 5, 2026, 9:05am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/3 "2026-05-05T09:05:08Z")
> [@Doug101](#): > > Tried updating the boot loader, but since I can communicate with the Arduinos, I can't. You need a programmer for that. > [@Doug101](#): > > I have a new (3rd) computer, Windows 10 where I downloaded the current IDE, 2.3.8 and it won't communicate either. Which is the version of the AVR board package that is installed on the **old** computers. You can find that out by enabling verbose output during compilation and checking the first few lines; you don't need to upload, just verify/compile. For IDE 2.3.8 it is more than likely 1.8.7. Somewhere along the line there was a change when Arduino introduced a Nano with a newer version of the bootloader. In the tools menu you can check the available processors. If there is only _328P_ and _168_, you're using an older version of the board package; if it also lists a _328P old bootloader_ you can try that. Try all two / three options. // Edit: for some reason I thought that this was about a Nano. You can ignore most of this post. ---
**Author:** ![sonofcy](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sonofcy/32/1283617_2.png) [@sonofcy](https://forum.arduino.cc/u/sonofcy)\ **Post date:** [May 5, 2026, 11:07am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/4 "2026-05-05T11:07:40Z")
There was a post I just saw with the same issue. It is a windows/driver issue and the fix is a little painful. Start [HERE](https://forum.arduino.cc/t/arduino-nano-code-not-uploading/1442672) ---
**Author:** ![david\_2018](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/david_2018/32/1013044_2.png) [@david\_2018](https://forum.arduino.cc/u/david_2018)\ **Post date:** [May 5, 2026, 11:49am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/5 "2026-05-05T11:49:25Z")
> [@Doug101](#): > > Both Arduinos are still running the code I last uploaded nearly 10 years ago. Is that code acting as a HID device? In which case you might have modified the code on the USB-to-serial chip rendering it unusable for the normal programming function. Do you remember if you ever programmed the boards using an ISP programmer? You may have left the boards without a bootloader installed when you stopped using them. ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [May 5, 2026, 1:07pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/6 "2026-05-05T13:07:45Z")
**IDE \>\> TOOLS \>\> BOARD \>\> AVR BOARDS \>\> your board** ... and ... **IDE \>\> TOOLS \>\> PORT \>\> your port**. ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 9:12pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/7 "2026-05-05T21:12:37Z")
I think they are clones. Attaching a pic of the Uno. I'm not sure about the Mega, but assume it is a clone as well. Both were working perfectly 9 years ago and have not been touched. Both are still running IDE 1.8.12. Using same computer Same USB cables If I plug the USB cable in a different USB port in the computer IDE updates to the new USB port. No errors in Device Manager. ![IMG_8252](https://europe1.discourse-cdn.com/arduino/original/4X/0/9/6/0961cc6892050c3a443292a8af70a7fd25fe4b69.jpeg) ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 9:18pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/8 "2026-05-05T21:18:08Z")
No, not HID device. (And not sure how to do that). When I last used the computer and Arduino boards I had 8 different sketches. I was switching between all 8, meaning I was able to one of the eight and upload and run it without any issue. ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [May 5, 2026, 9:27pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/9 "2026-05-05T21:27:58Z")
It will be a CH340 USB\<\>Serial driver issue. Windows seems to be on a mission to disrupt anything that comes from China. If you re-install that driver, it will update in the next boot. ---
**Author:** ![camsysca](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/camsysca/32/1015228_2.png) [@camsysca](https://forum.arduino.cc/u/camsysca)\ **Post date:** [May 5, 2026, 9:34pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/10 "2026-05-05T21:34:40Z")
@Wawa that re-update can be blocked by telling Windows the newer version is incompatible with your hardware. It works for me that way, anyway - but I've had to do it twice, IIRC. That information, as well, is in the posts by @pert on this topic. ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 9:49pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/11 "2026-05-05T21:49:47Z")
I think you mean IDE/Tools/Board and IDE/Tools/Port ![IMG_8257](https://europe1.discourse-cdn.com/arduino/original/4X/f/6/9/f69ebeda745aea48d8230b0997901bf5de451a01.jpeg) ![IMG_8256](https://europe1.discourse-cdn.com/arduino/original/4X/4/3/7/437669467ca834b139e8970547b0f73c541a074d.jpeg) ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 10:02pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/12 "2026-05-05T22:02:44Z")
Not sure how on a computer that's not been powered on in 9 years would know know we now have an issue China and China drivers. But who knows. Tried that last night. Still getting the same error. Tried Com1 and Com 4. Still not working. This is computer has not been on the Internet in 9 years. This is the only software modification that's been made. ![IMG_8253](https://europe1.discourse-cdn.com/arduino/original/4X/2/d/7/2d77d53bce245066b7a1c833b0944f724b5aea62.jpeg) ![IMG_8255](https://europe1.discourse-cdn.com/arduino/original/4X/2/a/a/2aa55e52a71e13a58655f2f97a52c6bf9adb92a4.jpeg) ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 10:20pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/13 "2026-05-05T22:20:01Z")
Just tried the following... And it looks like I am communicating with the board, but can't upload a sketch. 1. **Power Off the Board:** Completely turn off your Arduino board by removing the power source. 2. **Disconnect the USB Cable:** Unplug the USB cable from the board. 3. **Hold the Reset Button:** Press and hold down the Reset button on the board. 4. **Reconnect the USB Cable:** While still holding the Reset button, reconnect the USB cable to the board. ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 10:23pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/14 "2026-05-05T22:23:26Z")
Okay. Out of complete frustration I just ordered a new Uno board from Amazon. Paid $30, so I'm assuming it's a Genuine board. I'm as frustrated as frustrated could be. ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [May 5, 2026, 10:54pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/15 "2026-05-05T22:54:18Z")
> [@Doug101](#): > > avrdude: verifying ... > avrdude: verification error, first mismatch at byte 0x0000 > 0x62 != 0x0c Corrupt bootloader. > [@\[SOLVED\] verification error; content mismatch](https://forum.arduino.cc/t/solved-verification-error-content-mismatch/436352): > > Hello everyone, I've been using the Arduino Uno R3 SMD Edition for about two months but, just now, I've encountered this issue: avrdude: verification error, first mismatch at byte 0x0000 0x62 != 0x0c avrdude: verification error; content mismatch The message appears every time I try to upload any kind of program to the Arduino so I think it's a board problem. If you have any suggestions or need more information please reply! ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 11:02pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/16 "2026-05-05T23:02:14Z")
That's for a nano board. I have a Uno and a Mega. Tried it, and it doesn't work. ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 5, 2026, 11:15pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/17 "2026-05-05T23:15:58Z")
The two PC's I had been using have not been powered or updated in 9 years. No updates at all. Haven't been connected to the Internet when I powered them on. I have a 3rd and a fourth. Both are Windows 10 and are as up to date as a Windows 10 computer can be. I then installed the latest IDE. Getting same error message. Did you see my other post where I held down the Reset button? ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [May 5, 2026, 11:33pm UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/18 "2026-05-05T23:33:27Z")
> [@Doug101](#): > > for a nano board. I have a Uno Same microcontroller, I believe. ATmega328P. ---
**Author:** ![ptillisch](https://avatars.discourse-cdn.com/v4/letter/p/ad7895/32.png) [@ptillisch](https://forum.arduino.cc/u/ptillisch)\ **Post date:** [May 6, 2026, 3:10am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/19 "2026-05-06T03:10:00Z")
Hi @Doug101. I suggest we focus on one board at a time. The information that you are encountering problems with all your boards is interesting, but I think that we will like get too confused if we try to troubleshoot both boards at the same time. So let's focus on the UNO for now. > [@Doug101](#): > > avrdude: verification error, first mismatch at byte 0x0000 > 0x62 != 0x0c > avrdude: verification error; content mismatch When the " **Verify code after upload**" preference is enabled, after finishing an upload Arduino IDE reads the memory on the Arduino board and compares the read data against the data of the compiled sketch binary file on your computer that was uploaded to the board. When it did that, it found that the data on the Arduino board did not match what should have been there. This means the uploaded program was not written to the memory in the Arduino board during the upload process as expected. It is possible that a short or external circuitry connected to the Arduino board could cause this type of problem by interfering with the upload process. Make sure the board is not sitting on anything conductive that could short the contacts on the bottom of the board. Make sure there isn't any conductive debris (e.g., loose beads of solder, strands of wire, or component leads) on the board or on the surface the board is sitting on. I notice this large blob of solder: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/a/3/d/a3d899bd1ef936b274755800404cd39505c257c8.jpeg) Did you perform a repair on this board at some point, or did it come that way? If you have another USB cable on hand, try changing the cable. Maybe a damaged or defective USB cable could be the cause. Make sure the USB cable is fully inserted into the USB socket on the board and computer. If you have a shield or any external circuitry or components connected to your Arduino board, try this experiment: 1. Disconnect the USB cable of the Arduino board from your computer. 2. Disconnect any shields, modules, external circuitry, etc. from your board. 3. Connect the Arduino board to your computer with a USB cable. Now try uploading a sketch to the board again. Does the upload succeed? This experiment will determine whether the upload error was caused by interference from your external circuitry. If so, you can then focus your attention on identifying the specific problem with the circuit and resolving it. ---
**Author:** ![Doug101](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@Doug101](https://forum.arduino.cc/u/Doug101)\ **Post date:** [May 6, 2026, 5:44am UTC](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/20 "2026-05-06T05:44:01Z")
[ptillisch](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692/19) Thank you very much for your assistance. No repair was done on the board, but thanks to you suggesting there was an issue with the Uno board, I knew I had a couple of other Uno boards somewhere. Found 3 Unos, and each one worked as it should. I guess over the years a component failed, maybe there's some corrasion (I can't see in a trace) or there's a cold solder joint. After getting the Uno going, I tried the Mega. Some quick testing is looking like it's "sort of" working. It looks like I'm able to upload the blink code, I get an error and but the code runs fine. Or that's what I'm thinking. Here's something very strange. You identified what looks like sloppy soldering job. Yet when I look at the board, I can't find it. It's looking like it was an artifact from taking the picture. Maybe I used flash and that was a refection. (Sure doesn't look like that). I'm attaching a photo of the same board... Not seeing it. ![IMG_8261](https://europe1.discourse-cdn.com/arduino/original/4X/0/b/b/0bbf6a7617a2085eeea86b4a2fcbe869376ead89.jpeg) [Next page](https://forum.arduino.cc/t/problem-solved-defective-ardurino-board-im-stumped-cant-upload-any-sketches-to-uno-or-mega-i-could-9-years-ago/1442692.md?page=2)