No Power - Sanyo PLC-XF70 Service Manual

Troubleshooting

No Power

Check that POWER ON/OFF sig-
nal (IC_RESET_CPU) is correct.
L : Abnormality
Check that IIC
Bus signals are
correct.
IC801
CPU
IC886
PRESSURE SENSOR
TH901
TEMP. SENSOR
IC2541
TEMP. SENSOR
IC8801
TEMP. SENSOR
AC
INPUT
FUSE MAINS
SW
Is fuse (F901) blown?
Fuse may be opened
when either LAMP indi-
cator or READY indicator
does not light. Check
the fuse.
For safety, replace it with
a new fuse of the same
type
Occasionally, CPU may malfunc-
tion and need to be reset.
RESET for CPU
SW3801
Check that POWER FAIL
signals are correct.
L : Abnormality
POWER
FAIL
R/C
RESET KEY
CONVERTER
IC_RESET_CPU
POWER(DC)
POWER
NOISE
FILTER
PRIMARY CIRCUIT
Power sw
ON
Power on/off
Fan on/off
PFC on/off
Ballast on/off
400~600ms(Stability period of PFC.)
Are the LAMP indicator
(red) and READY indica-
tor (green) light?
If the LAMP and READY
indicators are not light,
check the primary circuit
and S5V of standby power
supply circuit.
Check that Vcc volt-
ages are correct.
IC5801
IO
IC1881
POWER
FAIL
DA
FAN
CONTROL
FAN
CONTROL
PF_PFC3/4
SWITCHING
POWER
SUPPLY
Check that PFC cir-
cuit on/off signals
are correct.
Power sw
Timing chart
OFF
Cooling time after power off.
- 126 -
-16-
Is the lamp cover attached cor-
rectly?
When the lamp cover is removed
or not attached correctly, the
projector cannot be turned on.
Check the lamp cover and the lamp
cover switch (SW902).
SW902--open: Abnormality
BLAST_SW3/4
INDICATORS
LAMP3/4 12VA
LAMP COVER SW
FAN
PF_
FANS
12V
FAN
P.F.C. BALLAST
1/2 1/2
Check that the Lamp
ballast on/off signals
are correct.
Check the tempera-
ture switches.
SW902
SW903/904
THERMAL SW
Check 12V
for PFC.
PF_TH
LAMP-1/2