Update: I started playing with a genuine Deumilanove and exactly same problem happened to it - d13 led blinking, but avrdude says stk500_recv(): programmer is not responding

I uploaded a largish sketch ~15kb to Arduino Nano v3.0 (clone) and that left the board in an unusable state. When connected to USB, a power LED goes on immediately and 1-2 seconds later the yellow "L" starts blinking really fast. Here's the board I use, it's a cheap clone, but it worked really well before today.

Now, when I try to upload a new sketch I get an error:

avrdude: stk500_recv(): programmer is not responding

I tried making and ISP programmer out of genuine Duemilanove, using nano's ISP pins and tried following official instructions (didn't use any capacitors/resistors). Either way when I click "Burn Bootloader" result is the same error:

avrdude: stk500_getsync(): not in sync: resp=0x15

I have connected "debug" leds to D7,8,9 and heartbeat fades in and out in idle, others stay dark. When I click "Burn Bootloader" all leds go dark then it does few quick blinks on 7, then similar pattern for 8, and then heartbeat resumes. Sometimes this sequence is repeated twice.

I also tried editing preferences.txt to bypass bootloader, but that didn't help.

How do I restore this board or do a low level reset? It seems to be in some failure mode, with pin 13 oscillating, but I don't know what that means.

  • Ahh I kinda remember something about holding the reset button while uploading might unbrick the Arduino enough to upload it, but I can't remember when to release the button (or if I'm just imagining this)... are you sure you have the right COM port set and all in the IDE? Jul 14, 2014 at 13:57
  • Yes, pretty sure the ports are right, because the programmer board blinks the leds differently when software tries talking to nano. Jul 15, 2014 at 3:55
  • The official instructions don't mention any capacitors (unless you use a bare chip). Could you show a picture of how you wired it?
    – Gerben
    Jul 15, 2014 at 18:05
  • It suggests a 10uF capacitor when using Uno. Anyway, I managed to restore the boards using a Reset button, see my answer below. I disassembled the wires afterwards so no pictures this time. Wiring was really straightforward, I might attempt it again, once I find a newer bootloader Jul 16, 2014 at 0:26
  • im have the same problem, Chinese Arduino 3.0 with CH340 USB controller, i was thinking the problem is CH340 failure, in my time this arduino is so cheap, i solve that by replacing the entire board, but in order to know whats cause the failure i will be testing changing the CH340 chip in this board. Oct 19, 2018 at 13:42

4 Answers 4


I successfully restored both boards using the reset button:

  1. Power off the board (I disconnected the USB cable from computer)
  2. Press and hold the reset button
  3. Connect USB cable (keep holding the reset button)
  4. Click "Upload Sketch"
  5. Wait a second or two until Arduino software says "Uploading..." in the status bar
  6. Release the reset button

Use these steps to upload any small sketch, Blink example is a good choice.

  • I've been blocked on this for 2 days, you just saved my board!
    – Julien L
    May 2, 2020 at 14:14

Use "upload.verbose=true" in the preferences.txt of the Arduino IDE (File->preferences-> Click on the file), this helps you to find the right moment to release the reset button (Step 5 of Paul's method).

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
         Using Port                    : COM19
         Using Programmer              : arduino
         Overriding Baud Rate          : 57600
release here ^^^^

Try changing processor type to ATmega328(old bootloader) in Tools->Processor. My Nano board blinked led like it had bootloader but I couldn't upload sketch and that helped.


There is bug related to watchdog in original old Arduino bootloader. You can switch to different bootloader, e.g. "Optiboot".

Explanation of issue from ATmega48A/PA/88A/PA/168A/PA/328/P datasheet, section 10.10.5 Watchdog Timer, page 48:

If the Watchdog is accidentally enabled, for example by a runaway pointer or brown-out condition, the device will be reset and the Watchdog Timer will stay enabled. If the code is not set up to handle the Watchdog, this might lead to an eternal loop of time-out resets. To avoid this situation, the application software should always clear the Watchdog System Reset Flag (WDRF) and the WDE control bit in the initialization routine, even if the Watchdog is not in use.

Reset from button is not helping, only power off/on reset give device change to boot again (and flash new software). Explanation of this, from 11.9.1 MCUSR – MCU Status Register, page 54:

Bit 3 – WDRF: Watchdog System Reset Flag This bit is set if a Watchdog System Reset occurs. The bit is reset by a Power-on Reset, or by writing a logic zero to the flag.

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