Just had a guy around with an A4 install he did himself, but had problems of flat battery after a few days and no rear speakers. he was supplied an A4 symphony to RNS-E cable. So I offered to take a look based on its probably a cable fault.
1. Pin 16, not 13 being used for amplifier power
2. ALARM wire connected to the TEL mute pin 11 and not pin 14
3. Both rront and rear line outs the wrong way around. hence no rear sound
Swapped everything around and all seems ok now. This is one of the reasons I always buy Kufatec cables, they work first time, every time.