3-19
ONE POINT REPAIR GUIDE
10. NO SOUND
There is no sound output in the USB function, repair the set according to the following guide.
10-1. USB FUNCTION
10-1-1. Solution
Replace IC501 on MAIN board, ICA201 on TOP board.
10-1-2. How to troubleshoot (Countermeasure)
1) Check +5 VU to USB board.
if +5.6 VA to pin1 of ICA201(LDO) doesn’t come out, check pin8 & 9 of CN106.
if +5.6 VA is normal & +5 VU of ICA201 pin2 doesn’t come out, then replace ICA201.
2) Check “Digital audio AMP block”.
10-1-3. Service hint (Any picture / Remark)
D
D+
D-
D-
(± 5 V )
(± 66.5 V )
DRIVER
IRS2092
OP AMP
AZ4580
FET
IRF6775
X 2
DRIVER
IRS2092
OP AMP
AZ4580
FET
IRF6775
X 2
MLC3730
Main DSP
(+3.3V_CD, VCC1.2)
USB1 USB2
IC201
ADC
CS5346
PRE, AMP
S4308
DAC
PCM5101
PS9860
PWM
DRM_WEN/CAS/
RAS/SEL/CLK/CKE
AMP_OSC
ADC_DATA
MCS_BCK/LRCK/MCLK
FRONT(SE)
SW(SE)
IR_IN_FL
FL_OUT_P/N
SW1_OUT_P/N
M00_15
A00_16
SF_DI/DO
SF_CS/SCK
500 W
MOT_MUTE,CLOSE,OPEN
D2S+/ -
IR_IN_SW
PW
M_L
R
C
K
/B
C
K
/DA
T
A
DSP_O
_
DA
TA
AU
X_
D
A
T
A
EX
P_DA
TA
MC
S_B
C
K/LR
C
K
, MC
LK
C
CD_RW/ MCLK/ LRCK/ BCK,
CD_DAT
CD_RST
UART_RX/TX
For AUX
For MIC
PGPC08
1.1
2.0
IC101
Micom
PCM1808
SCRATCH A/B,
M_VOL_A/B,
FAN_CTRL /2,
DJ Effect Scratch/Level
DRV632
DRIVER
IRS2092
OP AMP
AZ4580
FET
IRF6775
X 2
SW(BTL)
IR_IN_SW
SW2_OUT_P/N
500 W
1000 W
SF_DI/DO
SF2_CS/SCK
AUX OUT
AUX IN
TUNER
(FM/AM)
PTB
MIC 1
MIC 2
BT_TX/RX
BT_PCM_BUFFER
D1+/-
USB D+/D- (CN502 pin5, 6 & 8, 9)
< Waveform of USB D± signal >
< USB function signal
fl
ow >
Summary of Contents for OM7550
Page 13: ...1 12 ...
Page 16: ...2 3 Figure 3 Step 3 Seperate Cover_Side to out direction ...
Page 17: ...2 4 ...
Page 21: ...2 10 ...
Page 79: ...3 75 3 76 3 MAIN VFD RMC1 P C BOARD TOP VIEW ...
Page 80: ...3 77 3 78 4 MAIN VFD RMC1 P C BOARD BOTTOM VIEW ...
Page 81: ...3 79 3 80 5 FRONT P C BOARD TOP VIEW 6 FRONT P C BOARD BOTTOM VIEW ...
Page 82: ...3 81 3 82 7 TOP VOLUME_FR1 P C BOARD TOP VIEW ...
Page 83: ...3 83 3 84 8 TOP VOLUME_FR1 P C BOARD BOTTOM VIEW ...