Flowchart Of Failure Analysis For The Power Supply Unit - Pioneer krp-m01 Service Manual

5
[2] POWER SUPPLY UNIT

Flowchart of Failure Analysis for The POWER SUPPLY Unit

Failure analysis for the
POWER SUPPLY Unit => PS1
Yes
Is the STB 3.4V power output?
No
Is the output short-circuited?
No
After manual latching is released
for the STB power, is STB 3.4 V
power output?
No
Is the cable connected firmly to
the P2 connector?
Yes
Is the cable to the P2 connector
broken?
No
Is the fuse (F101) blown?
No
Is the cement resistor (R301)
blown?
No
The POWER SUPPLY Unit is
normal.
Failure analysis for the
POWER SUPPLY Unit => PS2
The unit is not turned on, even
though the Relay port is "H."
Does the Relay port remain "L"
after the unit is turned on with the
remote control unit?
Yes
Does a PD_TRG signal
become "H" temporarily?
No
Are V+6.5V, V+12V, and V+17V
outputs normal and not short-
circuited?
Yes
The POWER SUPPLY Unit is
normal.
5
6
Yes
Properly reconnect the P2
connector.
After disconnecting the P2 connector,
Yes
if STB3.4 V on the Power Assy is
still short-circuited, replace the
POWER SUPPLY Unit.
If the unit shuts it off again after
Yes
output restoration, replace the
POWER SUPPLY Unit.
No
Properly connect the cable between
the P2 and M1 connectors.
Yes
Replace the defective cable (J111).
Yes
Replace the POWER SUPPLY
Unit.
Yes
Replace the POWER SUPPLY
Unit.
Yes
Replace the POWER SUPPLY
Unit.
Yes
Replace the POWER SUPPLY
Unit.
No
If those outputs are not normal or
short-circuited after the P2
connector is disconnected, replace
the POWER SUPPLY Unit.
KRP-M01
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• A cause of failure may be that STB3.4 V voltage is below 3 V
(does not reach the specified value).
• If STB3.4 V voltage is not output, other four voltages (STB5.1 V, V+6.5 V, V+12 V,
and V+17 V) are not output.
• If Standby power is latched up for an extended period, the protection against
over voltage or over heat for STB3.4 V has been activated.
• Check the voltage at the MAIN BLOCK Assy and POWER SUPPLY Unit.
• In this case, failure in the RC101 rectifier diode is suspected.
• Check the resistance between the two electrodes of the cement resistor,
using a tester.
If the resistor is damaged, a failure in Z121 (STB power IC) or Q301 (Vcc power
switching FET) by short-circuiting is suspected.
• Check the voltage at pin of the Relay (Pin 2 of P2). (Voltage: 3 to 3.4 V)
• If the protection circuit against either Under Voltage Protection (UVP), Over Current
Protection (OCP), Over Voltage Protection (OVP), or Thermal Shut Down (TSD) for
Vcc power is activated, the PD_TRG signal becomes "H."
=> See "5.3 DIAGNOSIS OF PD (POWER-DOWN)."
• The PD_TRG signal is "H" only while the Relay signal is "H."
The PD_TRG signal becomes "H" only temporarily, because as soon as the main
board detects that the PD_TRG signal has become "H," it issues a command to set
the Relay signal to "L."
7
8
A
B
C
D
E
F
37
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