Although any firmware modification carries some risk it is unlikely that using RGNVoiceEditor caused the problem [even though there is a warning to that effect in both the other thread and turboccc's wikispaces page]. It is likely that the swapping back and forth from US to ID to US is the reason for it bricking. Different firmwares sometimes write info to other parts of the memory and when you then use another fw there can be a few bytes of info in the wrong place for the new fw. This can cause the unit to brick, and sometimes brick rather badly. This may be the reason that your unit bricked in the first place and it's possibly bricked again now.

Have you tried to force it on by holding the on button down for ~10 seconds while it's on charge?

You say '....., but worked when connected to usb'. Do you mean your PC can see it when connected by usb?

As much information as possible is needed.