— 6 —
POWER FAILURE CIRCUIT
Check the following if the unit is turned off by the power
failure detector.
1. Disconnect the AC power cord (120V AC line) for at least
10 seconds.
2. Connect a DC Voltmeter to the circuits shown below.
3. Press the Power key and check for the proper voltage
supplies.
4. If any of these voltages is low, the power failure detec-
tor should turn the unit off within three seconds.
5. Check all circuits shown below.
Note
: This unit is equipped with a Power Surge Protection
feature included in the CPU. If power failure occurs
three times within 15 minutes, the CPU will stop func-
tioning automatically to help prevent secondary
damage. (TV will not turn on by pressing the power
key.) To reset the operating programs within the CPU,
disconnect the AC power cord for at least 10 seconds.
This unit is equipped with a Power Failure Detector function
included in the CPU which checks for an abnormal condi-
tion in the chassis power supplies, including the power
supply for the LVDS (LCD Panel).
If, while the power is on, a failure is caused by any of the
following that results in a low voltage supply, the CPU will
turn the unit off in 1.5 seconds to prevent further damage:
•
Failure within the power supply circuits.
•
A short circuit in the load side from the supply.
1.
Power Failure:
Detected voltage failure for main board
and digital board circuits. (Connected to IC801 pin 32.)
2.
Power Failure (LVDS):
Detected voltage failure for LCD
panel. (Connected to IC801 pin 36.)
(Normal: High; Failure: Low)
If, while the power is off, the power is switched on and any
of these failures remains uncorrected, the CPU will shut off
the power within three seconds.
32
14
IC801 (CPU)
D1603
2
2
4,5
2
2
D1673
D1612
Q602
Q1673
Q607
Q610
Q611
D1602
36
Power Fail
Power On
Power Fail
2
(LVDS)
Power
Main
D1683
D1641
D1682
D1652
K8R
24V
IC1641
9V
IC1631
5V
D1651
33V
IC1601
3.3VD
IC1611
1.8VD
DM
PIN19
K6MA
IC1621
5/12V
LVDS
Q803
