XOCECO LC23K6, Service Manual

Page: 22 / 44

2
2. raster, but no picture
Check if the unit
can operation?
Check if the all
channels have signal?
Replacing
CPU board
Enter factory-menu,
operation CLEAR
EEPROM, then turn
off , turn on again , it if
display picture.
Adjust CPU board
again
Which is no
signal of
channels
Replacing CPU
board
Testing power
supply (
+
5V-V)
of video
processing board
Check input 24V
of sound
conversion board
Check input 24V-A
of CPU board
Check output 24V-A of
power supply board
Check if PIN2
1VPP signal
and noise wave
of P32?
Replacing
TUNER202
Check if PIN56
15.734KHz
sync signal of
U29?
Replacing U29
Display
“NO-SIGNAL”
Testing
1VPP signal
of TP1,
TP2, TP3.
Replacing CPU board
Replacing U13
Testing
PIN65 of
U30 SYNC
signal
Replacing
U30
no
yes
no
yes
no
no yes
VGA/DVI
TV
YPRPB
yes
yes
no
no
yes
no
no
no
no
no
yes