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 IC500 on MAIN board & IC104 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 CN502.
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 IC500.
b. Check USB± signals to CN502(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 CN502
D+ to pin 2&5 of CN502
< Waveform of USB D± signal >
< USB function signal fl ow >
PWM
FR,FL
12.288 MHZ
DSP IC500
176 PIN
USB1_D±
USB2_D±
Interrupt
controller
CDROM x8 speed
Decoder
NAND Controller
within BCH codec
14bits ECC
GDMA 3ch
ADC (12bit*5ch)
Timer, Watchdog
GPIO (72 Max)
SPI 4ch (Max)
RTC & Wake up
UART 4ch (Max)
I2C 2ch
SDHC-SDIO 4ch (Max)
USB 2.0 OTG
SRAM (10K)
Main Processor
Audio DSP-0
GDMA 2ch
I2S (7.1ch)
SPDIF (Rx, Tx)
ADPCM
PLL
Clock Controller
Reset Controller
Test Controller
Audio DSP-1
USB 1.1
Host/Device
ARM
926EJS
16KB
I-Cache
16KB
D-Cache
400Mhz
DSP
133Mhz
SRAM29KB
I-Cache 8KB
D-Cache 8KB
DSP
133Mhz
SRAM29KB
I-Cache 8KB
D-Cache 8KB
Boot ROM (20KB)
SDRAM
Controller
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