XOCECO LC-30K9A(W), Service Manual

Page: 27 / 58

2
5
NO PICTURE
can no
VGA
yes
no
D4 TV
no
yes
no
yes
no
no
no
no
no
yes
yes
yes
no
yes
yes
no no
Check whether display
LOGO in power on
No Display “box
searching”
Display “BOX
searching”
Check MONITOR
board power supply
Check whether
monitor board X402
connecting well
Replace MONITOR
board
Check If this set can
be operated by
R/C or push key?
All channels are
without pictures
Which channel
without picture?
Enter factory adjustment
menu,execute CLEAR EEPROM,
after operation shut off and re-put
on to check if there is a picture?
change
CPU board
Calibrate
CPU board
Replace CPU
board
Screen display
NO-SIGNAL
Determine
modulate power
supply +5V-V
Determine the
synchronization signal of
65th foot of U30
Replace
U30
Check U40
Determine pin3
foot of P32 if there
is 1VPP signal or
noise wave?
Replace
TUNA02
Determine 56th foot of U29
if there is 15.734KHz line
synchronization signal?
Replace
U29
Determine the
signal of
TP1,TP2,TP3,
they should be
1VPP
Replace U13
Replace
CPU board
Replace power
adapter