For the second production we fixed some errors so that the defect rate will be lower. Here is all the changes that I made :
- Audio resistor modification. Volume was too low on headphones, adjusting resistors values fixed the issue.
- Resistor preventing boot sometimes : Fixed
- RAM impedance control problem, making high % of defect units : fixed
- Ram voltage reduced to 1.35V to use DDRL3 (lower power consumption)
- Injection mold modification 1 : To prevent the on:off switch to twist on the side. Some users had problems with that.
- Injection mold modificaction 2 : Prevent assembly error of the Dpad silicon by operator while assembly.
You can make backup of your SD card on your computer. Using win32diskimager it's very simple.
Then if you get SD corrupted you can just use your backup.
Only problem is that backup image is big (size of SD, so 16 or 32GB)