3-13
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the USB FUNCTION, repair the set according to the following guide.
5-3. IN THE USB FUNCTION
5-3-1. Solution
Please check and replace IC502 on MAIN board & CN801 on FRONT board.
5-3-2. How to troubleshoot (Countermeasure)
1) Check +5V_USB to FRONT board.
If an insert, search, or file search on the VFD display USB Device into the USB jack, the voltage is okay,
if so not, check +5V to pin10 of CN801.
2) Check USB D± from MAIN board to FRONT board.
a. Check 1.1_D± signals(pin A7, A8 ) to IC502.
b. Check USB± signals to CN801(pin1, 2, 4, 5).
If there is any trouble, check the power for each IC.
The power is normal but , if the signal waveform to the IC is distorted or no signal, replace it with a new one.
3) Check if “Digital audio AMP block” on item 5-2 is normal.
5-3-3. Service hint (Any picture/ Remark)
< Waveform of USB D± signal >
< USB function signal
fl
ow >
Summary of Contents for OM4560
Page 13: ...2 2 ...
Page 17: ......
Page 49: ...3 34 3 33 BLOCK DIAGRAMS 1 SYSTEM BLOCK DIAGRAM ...
Page 51: ...3 38 3 37 3 AUDIO PATH BLOCK DIAGRAM ...
Page 52: ...3 40 3 39 4 POWER BLOCK DIAGRAM ...
Page 55: ...3 64 3 63 2 MAIN P C BOARD TOP VIEW BOTTOM VIEW ...
Page 56: ...3 66 3 65 3 FRONT P C BOARD TOP VIEW BOTTOM VIEW ...
Page 58: ...3 70 3 69 ...