Motorola V60 Series Manual page 73

Can radio audio be heard?
Yes – Replace the device now jumpered out. Power cycle the head control unit.
Can radio audio be heard?
Yes – Replaced device was defective. END
No – Inspect for damage on optical cable connecting to this device.
No – Put original device back in the D2B ring and repeat step 1 & 2 until all devices have been
bypassed. Go to LEVEL 2.
LEVEL 2: Head Unit Troubleshooting
1. Replace head unit.
Can radio audio be heard?
Yes – Original head unit defective. END
No – Inspect head unit optical cable for damage.
Is cable damaged?
Yes – Fix or replace damaged cable. END
No – All devices have been check. A defective cable is the most likely cause of the defect.
Use an optical jumper cable between devices to locate area of damaged cable.
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Call Mercedes-Benz Regional Technical Support Specialist for assistance if pre-wire cabling defect
cannot be located.
Mercedes Benz Telephone Manual v4.6
4.0 Troubleshooting Section
Date: 09/01/2004