PC-UM10M
LL-T1820-H/B TROUBLE SHOOTING
4 – 1
CHAPTER 4. TROUBLE SHOOTING
(Yes)
(Yes)
(Yes)
(Yes)
(Yes)
(Yes)
Green LED comes on when the power button is
pressed?
The screen is displayed properly in each video
mode?
AC cable is connected to the power supply
unit?
Input signal port is the one to which analog
signal cable is connected?
Test terminals LD416, LD417, and LD418 are
DC+3.3V?
Test terminal LD628 changes its level when
POWER switch is turned on and off?
Press INPUT key to switch over to the
correct input signal port.
Check the power supply unit and power
supply cable and their connections.
Check DC+5V power supply line (DV5A)
and POWER_CTL1 signal and circuits
around 0808.
Check DC+5V power supply line (AV5) and
POWER_CTL1 signal and circuits around
0808.
Check MAINPW signal and areas around
CN800.
Remove the analog signal cable. After a short
while time, the LED color changes form green
to orange.
(Yes)
(Yes)
(No)
(No)
(Yes)
(Yes)
(No)
(No)
(No)
(No)
(Yes)
(Yes)
(No)
(No)
(No)
(No)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(Yes)
(No)
(No)
(No)
Perform 1
B/L is lit?
No error.
Check AC cable connection.
Check power supply unit switch.
Check circuits around IC600.
Check circuits around IC400.
Check RESET circuit around IC602.
Check IC601 and clock circuit around X600.
Check SW100 and circuits around IC100.
The power supply unit is switched on?
SW100 is on 1st pin side?
Test terminal LD805 is DC+5V?
8th pin of 0808 is DC+5V?
4th pin of IC602 is in H level (DC+5 V)?
Test terminal LD809 is DC+5V?
C610-side terminal signal of X600 is normal?
Test terminal LD634 is DC+3.3V?
1
Perform 2
Perform 3
Perform 4
