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 IC501 on MAIN board & IC302 on USB board.
5-3-2. How to troubleshoot (Countermeasure)
1) Check +5V_USB to USB board.
If the USB LED are turned on, the voltage is okay, if so not, check +5.6 V to pin6 of CN302.
2) Check USB D1± or USB D2± from MAIN board to USB board.
a. Check 2.0_D1±signals(pin U7, U8 ) or 1.1_D1± signals(pin A7, A8 ) to IC501.
b. Check USB± signals to CN302(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)
D- to pin 1&4 of CN302
D+ to pin 2&5 of CN302
PWM
TAS5548
TAS5612LA
FR,FL
Woofer
12.288MHZ
TAS5612LA
DSP IC501
MLC3730
176PIN BGA
USB1_Ds
USB2_Ds
< Waveform of USB D± signal >
< USB function signal fl ow >
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