Test D: Poor Quality/Distorted/No Sound From All Speakers - THX(R) Audio System

PINPOINT TEST D: POOR QUALITY/DISTORTED/NO SOUND FROM ALL SPEAKERS-THX(R) AUDIO SYSTEM

D1-D3:

D3-D5:

D6:

Normal Operation
The audio unit enables the THX(R) amplifier through circuit CME27 (YE/VT). The THX(R) amplifier receives voltage through circuits SBB20 (GN/RD) and SBB21 (GY/RD), and ground through circuit GD148 (BK/YE).

The enable/clip circuit CME27 (YE/VT) carries out 2 functions: to turn the THX(R) amplifier on, and to monitor an overload condition to the THX(R) amplifier. In the event of an overload, the audio unit clips the audio output signal to the THX(R) amplifier (heard as distortion).

DTC U0184 - sets when network messages from the audio unit to the THX(R) amplifier are missing.

DTC U0238 - sets when network messages from the THX(R) amplifier to the audio unit are missing.

Possible Causes
- Fuse
- Circuit CME27 (YE/VT) open or short to ground
- Circuit GD148 (BK/YE) open
- Circuit SBB20 (GN/RD) open
- Circuit SBB21 (GY/RD) open
- THX(R) amplifier
- Audio unit