XOCECO LEC3205, Service Manual

Page: 22 / 71

20
Troubleshooting charts
1. No raster
Turn-on power supply, check
if the red indicator is light in
the STANDBY?
Check PIN7(12V output) of the
power supply board CN904
Check if it’s melted of FUSE
in the power supply board?
Replacing power supply board
Check the indicator in
turn-on condition
Check if the indicator is flicker
in the sensor control normal
condition?
Check if the CN905 output
24V
Check if the PIN26-30 of P4 is
high-level(5V)?
Check if it’s melted of F3?
Replacing CPU board
yes
no
no
no
Non-change color
blue
no
no
no
yes
yes
no
Check if the B of Q7 is
high-level?
Check if the pin 1, pin3 of U21
is high-level(5V)
Replacing U21
Replacing U22, U27
no
no
yes
yes