Help Only charges in car dock, but not by microUSB outside dock

[NewArtDroid]

I have owned this Droid Bionic car dock for a long time:
Motorola Vehicle Navigation Dock with Rapid Vehicle Charger for DROID BIONIC - Car Kit - Retail Packaging - Black
Amazon.com: Motorola Vehicle Navigation Dock with Rapid Vehicle Charger for DROID BIONIC - Car Kit - Retail Packaging - Black: Cell Phones & Accessories

I really like it. I almost always charge it within the car dock. Today I noticed that if I remove the microUSB that hooks into the car dock, and plug it into the phone, it will not charge. Does anyone know why?

Because the only wiring into the dock is the microUSB, does that mean the sound is LEAVING the phone via the microUSB (not the headphone jock) and then going to my stereo? I always thought music could not leave the phone through the microUSB, only through the headphone jack, but that's not how I understand the operation of this

 

[dashaus]

That's not a normal USB and it's says on it to not plug directly into phone bc it also various the audio as you've surmised.

 

[NewArtDroid]

That's not a normal USB and it's says on it to not plug directly into phone bc it also various the audio as you've surmised.

Does it pick up the audio through the microUSB, or is the the dock somehow hooking into the 3.5 mm headphone jack and transmitting that to the cable.

The reason I ask is that now I've upgraded to a Droid Maxx and I sure miss this dock. I'm still using the Droid Bionic in my car to listen to music, but that's not going to work, obviously, for telephone calls and GPS.

 

[dashaus]

Does it pick up the audio through the microUSB, or is the the dock somehow hooking into the 3.5 mm headphone jack and transmitting that to the cable.

The reason I ask is that now I've upgraded to a Droid Maxx and I sure miss this dock. I'm still using the Droid Bionic in my car to listen to music, but that's not going to work, obviously, for telephone calls and GPS.

The audio is routing thru the USB,I agree I miss that dock so much. So instead I hooked up a Bluetooth receiver to my audio in.

 

[NewArtDroid]

Wow, I never knew the Droid could transmit audio OUT the microUSB. I only thought it was out the 3.5 mm.