PIONEER DJ TSP-16, Service Manual

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TSP-16
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5.3 VOLTAGE MONITORING CIRCUIT
With this product, voltage of main power supply is monitored by FAULT_DET signal.
In the normal status, FAULT_DET signal is Hi level (+
3 . 3 V), however, in the abnormal status, it is at Low level (0V)
and it is detected by M1 UCOM (IC 8 005).
Voltage monitoring
If power supply failure is detected by FAULT_DET signal, M1 UCOM sets V +12 S W_CONT signal to Low to stop V+12 S W power supply
output that is supplied from AC adapter (DWR155 3 ) via FET (Q209).
Moreover, M1 UCOM displays that power supply abnormal is occurring by blinking MAKE UP button by LED_ S TBY signal.
To stop V+12 S W power supply output, all indications other than WAKE UP are turned OFF and all of S W and VR become unresponsive.
Symptom of product in abnormal status
If the voltage is abnormal, an error is detected when the voltage monitoring program starts operating after usual startup to stop V+12 S W
power supply output that is supplied from AC adapter (DWR155 3 ) via FET (Q209).
Thus, power supply is turned ON for approximately one second at the startup. While monitoring each voltage using an oscilloscope,
turn OFF and ON the power supply and check which voltage is abnormal for the voltages immediately before power supply is stopped.
* Be sure to check the part between each power supply and GND does not cause short-circuit before turning ON the power supply again.
Diagnosis method
Voltage monitoring circuit
Voltage monitoring voltage value
MAIN A SS Y IO A SS Y
PADB A SS Y S TBY A SS Y
V+OPA
V+5A
V+5A_REF
V+ 3 R 3 A
V-OPA
Regulator
Voltage
monitoring circuit
• DC-DC
Converter
• Regulator
• FET S W
M1 UCOM
(IC 8 005)
Voltage
monitoring circuit
V+5R1D
V+4R2D
V+ 3 R 3 D
WAKE UP
LED
(D9201)
LDO
(IC200)
FET
(Q209)
AC ADAPTER
(DWR155 3 )
LDO
(IC20 3 )
LED_ S TBY
Blinking in abnormal
status (red)
FAULT_DET
Hi :
Normal
Low :
Abnormal
Monitoring Monitoring
V+12
S
W
V+ 3 R 3 E
V+12E
V+12 S W_CONT
Hi : V+12 S W
output
Low : V+12 S W output stop
Always output at DC IN
IO A SS Y
MAIN A SS Y
Threshold value
Power supply
Overpower /
reduced
power
Detection range
considering variability
Center
value
Case when the monitoring functions
+ 6.0 8 V to 7.17V 6.61V IC201 IN/OUT short-circuit or short-circuit with different power supply
V+5R1D
- 3 .97V to 4.41V 4.19V S hort-circuit with GND or different power supply
+ 4. 88 V to 5.0 8 V 4.9 8 V IC202 IN/OUT short-circuit or short-circuit with different power supply
V+4R2D
- 2. 8 4V to 3 .51V 3 .17V S hort-circuit with GND or different power supply
+ 4.10V to 4.26V 4.1 8 V S hort-circuit with different power supply
V+ 3 R 3 D
- 2. 3 1V to 2.50V 2.40V S hort-circuit with GND or different power supply
V+OPA - 5.96V to 7.0 3 V 6.4 8 V S hort-circuit with GND or different power supply
V-OPA - -4.77V to -7.17V -5. 8 5V S hort-circuit with GND or different power supply
V+5A + 6.25V to 6. 8 2V 6.5 3 V IC5005 IN/OUT short-circuit or short-circuit with different power supply
V+ 6.25V to 6. 8 2V 6.5 3 V IC5007 IN/OUT short-circuit or short-circuit with different power supply
V+ 3 R 3 A + 4.05V to 5.2 3 V 4.62V IC5006 IN/OUT short-circuit or short-circuit with different power supply
+ overpower, - reduced power