37
KRP-M01
5
6
7
8
5
6
7
8
A
B
C
D
E
F
[2] POWER SUPPLY UNIT
Flowchart of Failure Analysis for The POWER SUPPLY Unit
Is the output short-circuited?
After manual latching is released
for the STB power, is STB 3.4
V
power output?
• 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 MAI
N
BLOCK Assy and PO
W
ER 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 (
V
cc power
switching FET) by short-circuiting is suspected.
• Check the voltage at pin of the Relay (Pin 2 of P2). (
V
oltage: 3 to 3.4
V
)
• If the protection circuit against either Under
V
oltage Protection (U
V
P), Over Current
Protection (OCP), Over
V
oltage Protection (O
V
P), or Thermal Shut Down (TSD) for
V
cc power is activated, the PD_TRG signal becomes “H.”
=> See “5.3 DIAG
N
OSIS OF PD (PO
W
ER-DO
WN
).”
• 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.”
If the unit shuts it off again after
output restoration, replace the
PO
W
ER SUPPLY Unit.
Properly reconnect the P2
connector.
N
o
N
o
After disconnecting the P2 connector,
if STB3.4
V
on the Power Assy is
still short-circuited, replace the
PO
W
ER SUPPLY Unit.
Yes
Yes
Yes
Yes
Is the cable connected firmly to
the P2 connector?
Properly connect the cable between
the P2 and M1 connectors.
Replace the PO
W
ER SUPPLY
Unit.
Replace the PO
W
ER SUPPLY
Unit.
If those outputs are not normal or
short-circuited after the P2
connector is disconnected, replace
the PO
W
ER SUPPLY Unit.
N
o
N
o
Is the cable to the P2 connector
broken?
Replace the defective cable (J111).
Yes
Yes
Is the fuse (F101) blown?
Replace the PO
W
ER SUPPLY
Unit.
Yes
N
o
Is the cement resistor (R301)
blown?
Yes
N
o
The PO
W
ER SUPPLY Unit is
normal.
The PO
W
ER SUPPLY Unit is
normal.
Is the STB 3.4
V
power output?
N
o
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?
Does a PD_TRG signal
become “H” temporarily?
N
o
Replace the PO
W
ER SUPPLY
Unit.
Yes
Yes
Yes
Are
V
+6.5
V
,
V
+12
V
, and
V
+17
V
outputs normal and not short-
circuited?
N
o
Yes
Failure analysis for the
PO
W
ER SUPPLY Unit => PS1
Failure analysis for the
PO
W
ER SUPPLY Unit => PS2
Summary of Contents for krp-m01
Page 8: ...8 KRP M01 1 2 3 4 A B C D E F 1 2 3 4 2 3 PANEL FACILITIES ...
Page 9: ...9 KRP M01 5 6 7 8 5 6 7 8 A B C D E F Remote Control Unit ...
Page 14: ...14 KRP M01 1 2 3 4 A B C D E F 1 2 3 4 4 BLOCK DIAGRAM 4 1 OVERALL WIRING DIAGRAM ...
