3-27
ONE POINT REPAIR GUIDE
NO SOUND
There is no sound output in the USB FUNCTION, repair the set according to the fol-
lowing guide.
6-2-1. IN THE USB FUNCTION
6-2-1-1. Solution
Please check and replace IC501, IC504 on MAIN board & IC3U01 on USB board.
6-2-1-2. How to troubleshoot (Countermeasure)
1) Check +5VU to USB board.
If +5.6VA to pin2 of IC3U01(LDO) doesn’t come out, check pin21~23 of CN103.
If +5.6VA 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, 17)
b. Check USB1/2_DN/DP signals from IC504 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”.
6-2-1-3. Service hint (Any picture / Remark)
kRGGXWGGju\WY
kT GGXXGGju\WY
USB
USB
Board
{T
IC504
USB2512B
/-
/-
AMP IC
TAS5631B
USB_D+/-
< Waveform of USB D± signal >
< USB function signal
fl
ow >
Summary of Contents for CM9520
Page 27: ...A60L A60R 4 SPEAKER SECTION 4 1 FRONT SPEAKER CMS9520F ...
Page 28: ...A80L A80R 4 2 REAR SPEAKER CMS9520S ...
Page 29: ...A90 4 3 PASSIVE SUBWOOFER CMS9520W ...
Page 81: ...3 52 9 VFD GRID CURRENT DRIVER Figure 9 joXayZY O wZW P joYaxZWXG l ...
Page 100: ...3 89 3 90 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD TOP VIEW ...
Page 102: ...3 93 3 94 2 MAIN P C BOARD TOP VIEW ...
Page 103: ...3 95 3 96 MAIN P C BOARD BOTTOM VIEW ...
Page 104: ...3 97 3 98 3 FRONT_VFD P C BOARD TOP VIEW BOTTOM VIEW ...
Page 106: ...3 101 3 102 6 FRONT_VOLUME P C BOARD TOP VIEW ...
Page 107: ...3 103 3 104 FRONT_VOLUME P C BOARD BOTTOM VIEW ...
Page 108: ...3 105 3 106 7 IPOD P C BOARD TOP VIEW BOTTOM VIEW ...
Page 109: ...MEMO MEMO 3 107 3 108 ...