I know this thread hasn't been active for a while, but having waded through countless related posts today, I was a little loath to start another one.
Basically, I am having the subject problem with my 3.3V 8MHz Pro Minis (they are of the Chinese variety). I have had the same issue with two processors (so far). I have been reading various posts, and following the suggestions therein all day without success. The problem started off as the “avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00” problem discribed elsewhere but has ended up with my seemingly having hosed the bootloader.
Suffice to say that I have tried two different 3.3V 8MHz Pro Minis, each with four different USB loaders (two SLAB varieties, another that identifies itself as A5XK3RJT, and an IDUINO UNO set up in ISP mode, with or without processor installed), using both IDE 1.8.5 (because one post suggested that this might fix the problem) and the most recent 1.8.10, on Mac OS X 10.11.6 and 10.14.5, and a whole range of different board options (including the 5V 16MHz Pro Mini, again because some posts suggested this might solve my problem), but all of these give the same result—the sync problem first up, and then when I tried to burn a new bootloader, the present problem.
I have tried loading a new bootloader using the ‘Arduino as ISP’ configuration, using the IDUINO UNO, on two separate Pro Minis (I have two more to play with, but I don’t really want to get them into the same state without a fix), with the same result—bascially the burn process fails, and now I'm left with two processors, seemingly without bootloaders...
The Pro Minis seem to be OK as delivered—they appear to be running the ‘Blink’ sketch when powered on, and they remain running the ‘Blink’ sketch (the original sync problem has meant that I am unable to load any other sketch over this) until I clobber the bootloader, when I end up where I now find myself.
The error log from typical burn processes are attached (too large to include in-line), but the typical failure message is as follows (this is the log from the attempt to burn the Pro Mini bootloader, but it's almost identical if I try the UNO (Optiboot) version):
Writing | ################################################## | 100% 0.00s
avrdude: 32652 bytes of flash written
avrdude: verifying flash memory against /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/bootloaders/atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex:
avrdude: load data flash data from input file /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/bootloaders/atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex:
avrdude: input file /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/bootloaders/atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex contains 32652 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 0.00s
avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x7800
0x00 != 0x0c
avrdude: verification error; content mismatch
avrdude done. Thank you.
Error while burning bootloader.
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
Photo also attached (I hope—there was a message at one point suggesting that there may have been a problem uploading it, and the preview doesn't seem to show whether or not it's actually there), just in case that triggers anything with anyone.
There is plenty of promising LED flashing (on both the UNO and Pro Mini) during the attempt to burn the bootloader, and the log messages would appear to confirm that all the 'communications lines' are open, but there is clearly a problem somewhere in the verification process.
It seems that quite often discussion leads to a solution, even if not directly, so any help would be appreciated, especially if it applies to experience with 3.3V 8MHz Chinese Pro Mini clones.
191110 Mini Log File.txt (9.58 KB)
191110 Uno Log File.txt (9.49 KB)