3-15
ONE POINT REPAIR GUIDE
5. NO SOUND IN THE USB FUNCTION
There is no sound output in the USB function, repair the set according to the following guide.
5-1. USB FUNCTION
5-1-1. Solution
Replace IC501 or IC303 on MAIN board.
5-1-2. How to troubleshoot (Countermeasure)
1) Check USB_5V to MAIN board.
if +5.1 VA to pin5 of IC303(LDO) doesn’t come out, check pin4 & pin5 of CN503.
if +5.1 VA is normal & USB_5V of IC303 pin1 doesn’t come out, then replace IC303.
2) Check “Digital audio AMP block”.
5-1-3. Service hint (Any picture/ Remark)
D
D+
D-
D-
USB D-/ D+ (CN503 pin4, pin5)
< Waveform of USB D± signal >
< MAIN board top view >
CN503
CN503
Summary of Contents for CJ87
Page 17: ...1 16 ...
Page 19: ...2 2 ...
Page 21: ...2 6 2 5 ...
Page 23: ...2 8 A60 3 SPEAKER SECTION FRONT SPEAKER ...
Page 69: ...3 40 ...
Page 73: ...3 47 3 48 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD DIAGRAM TOP VIEW ...
Page 75: ...3 51 3 52 2 MAIN P C BOARD DIAGRAM TOP VIEW ...
Page 76: ...3 53 3 54 MAIN P C BOARD DIAGRAM BOTTOM VIEW ...
Page 77: ...3 55 3 56 3 FRONT P C BOARD DIAGRAM TOP VIEW ...
Page 78: ...3 57 3 58 FRONT P C BOARD DIAGRAM BOTTOM VIEW ...
Page 79: ...3 59 3 60 4 JACK P C BOARD DIAGRAM TOP VIEW BOTTOM VIEW ...