Test E: No Sound From All Speakers - THX(R) Audio System

PINPOINT TEST E: NO SOUND FROM ALL SPEAKERS - THX(R) AUDIO SYSTEM

E1-E4:

E4-E5:

Normal Operation
The audio unit enables the THX(R) amplifier through circuit CME31 (BU/GN). The THX(R) amplifier receives voltage through circuits SBP38 (BN/RD) and SBP40 (VT/RD), and ground through circuit GD114 (BK/BU).

The enable/clip circuit CME31 (BU/GN) 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).

Possible Causes
- Fuse
- Circuit CME31 (BU/GN) open or short to ground
- Circuit GD114 (BK/BU) open
- Circuit SBP38 (BN/RD) open
- Circuit SBP40 (VT/RD) open
- THX(R) amplifier
- Audio unit