Samsung UD6400 Training Manual page 61

Trouble Shooting – No Sound
1. Check the Speaker sound data at CN301
2. Check the Monitor out sound data at CN302
3. Does the SODIF OUT sound data appear
at ? CN303
Check the source and check the connection
of sound cable (Comp/PC/DVI to HDMI) ?
YES
Check the signal at input of Main board?
AV1, COMP1 R : R541 / L : R539
PC, DVI R : L401 / L : L402
YES
Check the DATA between the Audio IC's ?
Pin #15 of IC301 : Mclk
Pin #20 of IC301 : LRclk
Pin #22,#23 of IC301 : I2C_DA/CL
YES
YES
Replace speaker ?
No
Input the sound source properly.
NO
Check CN501, CN402.
Change the Main Assy.
NO
Check IC301, IC303.
Change the Main Assy.
NO Check IC301, IC303.
Change the Main Assy.
NO
Please, Contact Tech support.