Voltage Monitoring Circuit - PIONEER DJ XDJ-XZ Service Manual

5

5.4 VOLTAGE MONITORING CIRCUIT

Voltage-Monitoring
This unit monitors the voltages of the main power-supply ICs, using the F_DET (FAULT_DET) signal.
The F_DET signal level is high (+3.3 V) during normal operations. When the level becomes low (0 V), detect abnormality
in the ERP UCOM (IC4502).
Product behavior when an error is generated
If power failure is detected with the F_DET signal (F-DET signal consists with the interval Low levels more than 50 ms),
the ERP UCOM will stop supplying the V+12D/V+12L/V+12A power from SW POWER SUPPLY, setting the PWR_ON
signal to low.
The ERP UCOM also informs of power failure with flashing of the MASTER REC (WAKE UP) (red LED) button, by sending the
WAKEUP_LED signal:
As the V+12D/V+12L/V+12A power is stopped, the indications other than the MASTER REC (WAKE UP) are unlit and all the
switches and VRs are disabled. When you let you return from a power supply abnormality detection state, perform drawing and
inserting of the power cord.
Diagnostic procedure
Note: 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+12D/V+12L/V+12A power from SW POWER SUPPLY will be stopped.
Identify which power-supply IC is defective, by duplicate drawing and inserting of the power cord while monitoring each
voltage with an oscilloscope. Check the value of each voltage immediately before stopping power supply.
Voltage-Monitoring Circuit Block diagram
B
AUDIO ASSY
V+12A
V+12D
DC/DC
V+12L
Converter
Regulator
AF
SW POWER
SUPPLY
V+12E
Regulator
Logic
Inversion
(Q6601)
xEUPSW
5
6
V+15A V+5D
V-15A V+9LED
V+5A
V+5AREF V+3R3D_CLK
V+3R3A V-7R5HP
V+3R3D1
A
V+5D
V+5LED
V+9LED
V+12L
DC/DC
V+12D
Converter
PMIC
Monitoring
V+5E
6
7
Monitoring
Voltage
Detection
Circuit
FDET(A_FDET)
High : Normal
Low : Abnormal
MAIN ASSY
G
V+5D
V+1R25D
F_DET(FAULT_DET)
V+4R2D
High : Normal
V+3R3D
Low : Abnormal
V+5D
Voltage
Detection
Circuit
PWR_ON
High : V+12D/V+12L/V+12A
Low : V+12D/V+12L/V+12A
T
XDJ-XZ
7
8
UCOM ASSY
Monitoring
V+5LED
Over
V+9LED
Current
Detect
V+12BL
V+5LED_DET
V+9LED_DET
V+12BL_DET
High : Normal
Low : Abnormal
V+3R3E
ERP UCOM
(IC4502)
Regulator
Output
No Output
WAKEUP_LED
DCK2 ASSY
MASTER_REC
Abnormal :
/WAKEUP
Flashing(Red)
LED
(D9026)
8
A
B
C
D
E
F
35