Today I revived 6 broken bluetooth modules. Turned out the serial eeprom needed to be reprogrammed.
So I took a working module, read the eeprom and programmed the eeprom of the not functioning bluetooth module and bingo it worked again.
The catch is you have to remove the eeprom to read and write to it correctly and you need an eeprom programmer that supports the m24c32-s eeprom (that is what I am using on my vp-190 programmer.)
It works like a charm although I managed to ruin