I have a Chinese clone pro mini m328p that has appeared to be bricked. Usually, I use my Uno with the ISP sketch to upload sketches to the pro mini (Vcc to 5V from Uno) (the reason to not using bootloader is due to some hardware peculiarity associated with this clone, the reset prior to sketch upload does not work). Everything seemed to work quite fine until I made the following changes to experiment with low power modes.
1) Changed fuse settings, and removed clock crystal to use the internal 8Mhz oscillator. The command I used to change the fuse setting is :
avrdude -C ... -c avrisp -P COM7 -b 19200 -p m328p -v -e -U lfuse:w:0xE2:m -U fuse:w:0xDA:m -U efuse:w:0x07:m
As is evident from the commandline , I have also disabled the brown out detection functionality, and the low fuse setting indicates internal clock source with a long boot delay. Avrdude tells me everything is fine and the fuse settings read back all okay. At this point, I've uploaded quite a number of sketches and they all work as expected.
2) I then proceeded to remove the voltage regulator. After this step, I've verified with my digital meter that in deep sleep mode, the current consumption is very low at 0.6uA, which is fantastic. At this point, I've uploaded many number of sketches and they all work as expected.
3) Changing the Vcc on the pro mini from 5v to 3.3v, I then uploaded another blink sketch with 3.3v Vcc. This step bricked the pro mini clone. I do not have a screenshot of the IDE, but the error message has to do with verification error at some code offset (possibly at 0x0000) .
After step 3) whenever I try to upload a sketch (with 5V Vcc) I get this error: http://pastebin.com/raw.php?i=rwfe8ram
I could also try to set fuse settings, the error message for that is: http://pastebin.com/raw.php?i=YgqDe5L3
The pro mini still blinks its light when I press the reset button on the Uno ISP. I have tried to solder back the 8Mhz crystal , but that does not help. When the 8Mhz crystal is soldered back onto pro mini clone, it will stop responding even to the Uno ISP reset buttons.
I have double checked my wiring and replaced the cables, still the same bricked pro mini clone. Wiring is the same as from Arduino ISP wiki page (10->RST, 11->11, 12->12, 13->13 , and Vcc, Gnd)
Please assist. Thanks