IF-172 Board Flowchart
VFD does not light
Is there voltage about 5.8V at PS1201?(MB board)
No
Check the +5.8V at CN702 pin7
Is there the FFC disconnected from CN702?
Is pin5 of IC702 oscillating?
Yes
Is there input of pulse to pins 7, 8 and 9 of
IC702?
Yes
Replace IC702
If the symptoms do not improve,
replace the
IF
board
Yes
Yes
Replace PS1201(MB Board)
If the symptoms do not improve, replace
FR Board
Check the circuits surrounging the
DCDC
CONVERTER.
Is there voltage at CN702 pin11?
Replace IC702. If no effect, replace the
FR Board
No
No
9-9
To IF con flowchart
No
No
Check the pattern around CN1204(MB board)
If the symptoms do not improve, replace
MB Board
No
Reconnect the FFC
If the symptoms do not improve, replace
FFC
Yes
Is there voltage about -25V at JL701?
No
Yes
Is the voltage of 3.3V at IC702 pin 43
and pin13?
No
Yes
Check the pattern 3.3V line of FR board
Yes
To IF con flowchart
No
Is there input pulse to CN702
pins 13, 15 and 16?
To IF con flowchart
Is the FFC disconnected
from CN702?
Replace FFC. If the symptoms do not
improves, replace IF board
Is there input pulse to CN1204
pins 13,15 & 16
Reconnect the FFC
If the symptoms do not improve,
replace FFC
Yes
No
Yes
No
No
Check FFC disconnected from
CN702 or broken
Reconnect the FFC
If the symptoms do not improve, change
the IF board
Yes
change IF board
No
BDP-S485