Voltage Monitoring Circuit - PIONEER DJ AlphaTheta CDJ-3000 Service Manual

1

5.4 VOLTAGE MONITORING CIRCUIT

g Voltage-Monitoring
A
This unit monitors the voltages of the main power-supply ICs, using the xFDET signal.
The xFDET signal level is high (+3.3 V) during normal operations. When the level becomes low (0 V), detect abnormality
in the PANEL CPU (IC7202).
g Product behavior when an error is generated
The SOURCE indicator flashes in red.
As the V+12TPS, V+12D, V+12A power is stopped, the indications other than the SOURCE indicator are light off and all the
switches and VRs are disabled.
The PANEL CPU will stop supplying the V+12TPS, V+12D, V+12A power from SW POWER SUPPLY, setting the EUP_CTRL
signal to low.
B
g Diagnostic procedure
Caution : Each time before turning the unit ON, make sure that each power-supply IC is not short-circuited to GND.
If any voltage is abnormal, that error will be detected by the voltage-monitoring program after it is started after a usual
startup of the unit. Then the V+12TPS, V+12D, V+12A power from SW POWER SUPPLY will be stopped.
C
Identify which power-supply IC is defective, by repeat power supply ON/OFF while monitoring each voltage with
an oscilloscope. Check the value of each voltage immediately before stopping power supply.
MAIN ASSY
D
SW POWER
V+12A
SUPPLY
V+12D
V+12TPS
SMPS_STBY
V+12E
E
V+12E is always output in AC IN,
regardless of power supply SW ON/OFF.
g Voltage value and Current value of the voltage-monitoring section
Power UVP OVP
V+12LED - -
V+12DEN - -
V+5R2LED 2.58 V 7.4 V
V+12FAN 2.58 V -
V+5D 2.58 V 7.4 V
V+12BL0 - -
F
BL1_A - -
30
1
2
!Regulators
!DC-DC Converters
!V+12LED
!V+12DEN
!V+5R2LED
!V+12FAN
!V+12BL0
!BL1_A
PMIC
(IC1201)
!V+5D
PMIC
(IC1401)
!V+3R3D
Hi : POWER ON
Low : POWER OFF
DTR
EUP_CTRL
(Q1003)
OCP Power UVP
0.89 A V+3R3D 1.92 V
0.89 A V+AUDIO 2.58 V
1.275 A V-AUDIO -2.58 V
- V+5DAC_L -
2.6 A V+5DAC_R -
1.1 A V+5SPDIF -
0.89 A V+3R3DAC_D -
CDJ-3000
2
3
Voltage-
monitoring
circuit
Over current
detection
circuit
Hi : Normal xFDET
Low : Abnormal
DC-DC
V+3R3E
(IC1003)
OVP OCP
6.8 V -
- -
- -
7.4 V -
7.4 V -
7.4 V -
6.8 V -
3
4
AUDB ASSY
!Regulators
!DC-DC Converters
!V+AUDIO
!V-AUDIO
Voltage-
!V+5DAC_L
monitoring
!V+5DAC_R
circuit
!V+5SPDIF
!V+3R3DAC_D
PNLB ASSY MLCB ASSY
PANEL
CPU EUP LED
EUP_LED
(IC7202) (D6240)
Abnormal :
Flashing(Red)
4