Mitsubishi Electric LT-2220, Руководство по обслуживанию

Страница: 43 / 56

2-2. No picture displayed and picture errors of Component signal.
Enter an input of D1(480i) gray scale in J201
connector, and select COMPONENT1 (or2) INPUT.
(Push the device UP button once.: twice in the case
of COMPONENT2)
And then, perform AV reset by front switch.
The video level inputs about 1.0Vp-p.
YES
Is OSD available?
NO
YES
Problem is in IC300 or IC4A0 or IC4A1
(and peripheral circuits). Are the
specified voltages available at the
connectors below?
NO
CN
Name
Pin No. Voltage
S5V J303 12 5Vdc
S3.3V J303 13 3.3Vdc
D3.3V J190 7 3.3Vdc
Psave1* J712 5 3.3Vdc
*control signal of D3.3V
YES
Problem is in the following
circuit (and peripheral
circuits) .
Voltage with
problem
PWB
including
the circuit
in problem
S5V SET(SUB)
S3.3V SET(SUB)
D3.3V SET(SUB)
Psave1 MAIN
1.0Vp-p
Is all harness connected correctly?
(especially between PWB-MAIN
and LCD PANEL (J4A0-LCD))
NO
Poor harness connection or
defective cable.
Is the digital video signal available at pin 14(G_7)
of IC4A1, and control signals of 3Vp-p available at
pins 27(HS : R4H6) and 28(VS : R4H5) and
31(CLK : R4H3) and 30(DE : R4H4) of IC4A1 ?
27 of IC4A1
28 of IC4A1
(f=60Hz)
3Vp-p
3Vp-p
H
V
14 of IC4A1
(MSB of Green)
3Vp-p
31 of IC4A1
(f=70MHz)
3Vp-p
(f=48KHz)
30 of IC4A1
3Vp-p
(f=48KHz)
IC300 or IC4A0 (and
peripheral circuits) are
out of order.
(PWB-
MAIN)
NO
LCD-module or IC4A1
(PWB-MAIN) are out of
order.
YES
Page 43
MODELS: LT-2220
/ LT-2240 /
LT-3020
/ LT-3040 / LT-3050