storch

2009 997.2s with the OEM Bose system.

issue was that intermittently the sound would come and go and the screen remained powered up like nothing is wrong, assuming it was the stereo head unit going bad I just had a Sony CarPlay system installed along with the needed NAV tv kit.

low and behold $1300. and a day later and the problem still exists??

Can it be the amp or something else?

German888

I would see if the place that did your install can bypass the factory amp to rule that our first. Can't imagine that not being the cause at this point.

semicycler

Yeah, amp is common in both setups. Start there.

OKB

dont know what he has but the radio can be reset and updated at the dealer and it will fix sound on/off problem

semicycler

Yeah but it happened with the original OEM radio. Then he upgraded to an aftermarket radio and it's still happening. So it's not the head unit itself. It's something else.

storch

Yea it's the same with both the original head unit and the new one.

if it is the amp what do I replace it with? Guessing a used OEM Bose unit may be the only option.

i only replaced the head unit was to correct the problem, otherwise I would have had no reason to replace it.

the stereo shop that did the install will work with me to fix it, this was the surprisingly the first time they did a NAV tv fiber optic kit and I am sure the parts are on me thought.

semicycler

Honestly anything is a guess at this point. It might be the amp is going (overheating?). It might be a loose connector at the amp. Or wiring - but it would need to be common to all speakers or perhaps power/ground to the head unit.

I still think the amp is a good place to start, but it's just a guess. You could try swapping it with another one. Or you could replace the OEM amp entirely with an aftermarket one. The MOST-Hur device would be removed, as would the optical bus. Then new wires run from the head unit to the amp, and the amp reconnected to the speakers. But now you have gone from an intermittent OEM system fix to a complete head unit/amp replacement system. That's got to be a pretty big dent in the wallet...

German888

Great opportunity to build the foundation for a sweet sound system though.

Iceter

Got any other unexplainable electrical gremlins?

Before I replaced my battery, the audio issue you describe was one of the many gremlins that were popping up around the car. Dealer couldn't duplicate it but it happened often. Everything would appear to work, but not a peep from any of the speakers.

Got a new battery and it's never happened again.

Its a shot in the dark, but I'd hate for you to spend a ton of time and effort trying to track down the cause if it's something very simple.

Sooner

I was having this issue intermittently, then it started happening every time I started the car. I discovered it was an issue between my Iphone 7 and the PCM. If I disabled Bluetooth, everything worked fine. My solution was to delete the phone out of the PCM and delete the PCM out of the phone. Then I reconnected them and immediately turned off the Phone Book Sync. Have no had an issue since then (about 2 weeks now).

Not sure if this will help you or not, but it seems to have solved my issue. Never had a problem until I switch to the Iphone 7.