Sanyo DP32640 Troubleshooting Manual page 3

Repair Flow Chart: Trouble Condition
Green Power LED is on, but LCD backlights are not on.
Backlights do not turn on, or only turn on and back off.
Power LED turns ON.
But, LCD Backlight is not ON, or only
turned ON and then back OFF.
Is the 12V supplied from
Power Bd.?
(see TABLE*1.0)
yes:12V
Is the 24V (if applicable) supplied from
Power Bd. during LED ON time?
(see TABLE*1.1)
yes: 24V
or
(not applicable)
On Main Bd.:
Is the "BL_ON" voltage (3.3V)
supplied from Main Bd.?
(see TABLE*3.0)
yes: 3.3V
Confirm wire harness connection between Main
Bd. & Power Bd., and between Power Bd. and
Inverter Bd.
Inverter Bd. or LCD Panel is not working.
1st: Replace "Inverter Bd."
If Inverter Bd. does not correct problem, then:
2nd: Replace "LCD Panel"
(TABLE *1.0) 12V Test Points
26" Models 32" Models
DP26640-00 N8ME DP32640-00 N8LE
DP26640-01 N8MF DP32640-01 N8LF
DP26640-02 N8MG DP32640-03 N8LH
DP26640-04 N8MH
(TABLE *1.1) 24V Test Points
26" Models 32" Models
DP26640-00 N8ME DP32640-00 N8LE
DP26640-04 N8MH DP32640-03 N8LH
DP26640-01 N8MF DP32640-01 N8LF
DP26640-02 N8MG
(TABLE *2.0) Main Bd.: "Power ON/OFF SW" Test Points
26" Models 32" Models
DP26640-00 N8ME DP32640-00 N8LE
DP26640-01 N8MF DP32640-01 N8LF
DP26640-02 N8MG DP32640-03 N8LH
DP26640-04 N8MH
(TABLE *3.0) Main Bd.: "BL_ON" Test Points
26" Models 32" Models
DP26640-00 N8ME DP32640-00 N8LE
DP26640-01 N8MF DP32640-01 N8LF
DP26640-02 N8MG DP32640-03 N8LH
DP26640-04 N8MH
no: 0V
On Main Bd.
Is 5V supplied to "Power ON/OFF SW"
(see TABLE*2.0)
yes: 5V
Replace: "Power Bd."
and "Wire Harness"
no: 0V
Unplug the cable from Power Bd. to
Inverter Bd..
Is the 24V supplied from Power Bd. during
LED on time?
no: 0V
Power Bd. is not working.
Replace "Power Bd.".
no: 0V
Main Bd. is not working.
Replace "Main Bd."
12V on Main Bd.
Main K8C "pin 8"
24V on Power Bd.
n/a
Power Bd. K603 "pin 1"
Power ON/OFF SW on Main Bd.
Main K8C "pin 1"
BL_ON Command
Main K8C "pin 13"
page 2
no: 0V
Main Bd. is not working.
Replace "Main Bd."
Inverter Bd. is not
yes: 24V
working. Replace
"Inverter Bd.".
Confirmation Voltage
12 V
Confirmation Voltage
n/a
24 V
Confirmation Voltage
5 V
Confirmation Voltage
3.3 V