3-17
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the USB FUNCTION, repair the set according to the fol-
lowing guide.
6-2. IN THE USB FUNCTION
6-2-1. Solution
Please check and replace IC501, IC504 on MAIN board & IC3U01 on USB board.
6-2-2. How to troubleshoot (Countermeasure)
1) Check +5VU to USB board.
If +5.6 VA to pin2 of IC3U01(LDO) doesn’t come out, check pin4, 5 of CN502.
If +5.6 VA is normal & +5VU of IC3U01 pin3 doesn’t come out, then replace IC3U01.
2) Check USB D± from main board to USB board.
a. Check USB_HUB_DN/DP signals to IC501(pin16, 18)
b. Check USB1/2_DN/DP signals from IC501 to CN502 (pin1, 2, 9 & 10)
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”.
6-2-3. Service hint (Any picture / Remark)
j k GkzwG
t sjZ^WW
j v kljGW
j v kljGX
t j rVsyjrVijr
w z `_\[
w ~ tGpj
j z \Z[]
h k jGpj
h r \Z\_
h k jGpj
m Gtpj
h k jkh{h
t p jkp
k h jkh{h
IR AMP
IRF6775
USB
Board
{T
IC504
USB2512B
/-
/-
USB_D+/-
< Waveform of USB D± signal >
USB D+ / D- (CN502 Pin1, 2 & 9, 10)
< USB function signal
fl
ow >
Содержание CM9730
Страница 11: ...MEMO 1 10 ...
Страница 13: ...MEMO 2 2 ...
Страница 59: ...MEMO 3 42 ...
Страница 83: ...3 89 3 90 2 MAIN P C BOARD TOP VIEW ...
Страница 84: ...3 91 3 92 MAIN P C BOARD BOTTOM VIEW ...
Страница 85: ...3 93 3 94 3 VFD P C BOARD ...
Страница 86: ...3 95 3 96 4 MAIN VOLUME P C BOARD 5 MIC P C BOARD ...
Страница 87: ...3 97 3 98 6 JOG P C BOARD 7 USB P C BOARD 8 TUNER P C BOARD ...
Страница 88: ...3 99 3 100 9 SPEAKER LED_MAIN P C BOARD TOP VIEW 10 SPEAKER LED P C BOARD TOP VIEW BOTTOM VIEW BOTTOM VIEW ...
Страница 89: ...3 101 3 102 MEMO MEMO ...