Installed in an Audi A4. front speakers are powered by the internal amp, rear and subwoofer are getting their signals from the RCA pre-amps and still using the factory amp. While on the road, my front speakers just quit working and only my rear speakers and subwoofer continued to work. I reset the unit twice but still no sound to the front speakers.

Any Ideas as to what happened? Is this is known problem with a easy fix?

good question!!! I see were in the same boat except i have no sound at all.. hope someone can help us!!!

Sounds like one of the speaker leads is shorting causing the z1's internal amp to shut down to protect itself from being ruined. In other words check your connections and make sure everything is taped up securely.