Fujitsu Plasmavision PDS4208W-B Service Manual page 16

Check 2
Start
Is voltage
at connectors
No
P505 q, t, o and
P8202 q on DC/DC
power PCB
24V ?
Yes
Is voltage at connectors P505
and P507 on the DC/DC power
PCB normal ?
No
(1) P505 !0 , P507w, 0 V to
4.3V or 6.6V to 7.0V
(2) P505 w, y 12.0V to 13.0V
or 0V
Yes
Is fan rotary signal of DC/DC
power PCB normal ?
(1) P505 !1 , P507e, 0Hz or
No
19.6Hz to 103.7Hz
(2) P505 e, u 120.3Hz to
168.7Hz or 196.6Hz to
256.3Hz
Yes
Fan protector operated
Power lamp: Flashes once intermittently in red.
(for 0.5 sec. at an interval of 3 sec.)
Is voltage
at connector
CN103 u, i on Power
Supply Unit
normal ?
(24V)
Yes
DC/DC power Power Supply Unit
circuit faulty circuit faulty.
Replace Power
Replace DC/DC
Supply Unit.
power PCB.
Vs and -Vy must be
adjusted.
Microcomputer
peripheral circuit
faulty.
Fan faulty
Microcomputer
peripheral circuit
faulty.
Check 3
Start
No
Is ambient temperature
of PDP unit less than
47°C ?
Yes
Does unit
operate normally
when temperature sensor PCB
is changed ?
Yes
Replace
Main/Digital
PCB Assy.
Replace fan.
Replace
Main/Digital
PCB Assy.
Temperature protector operated
Power lamp : Flashes intermittently twice in red.
(for 0.5 sec. at an interval of 3 sec.)
Adjust PDP unit installation so that
peripheral temperature is 40.0°C or
No
less.
Microcomputer
peripheral circuit
No
faulty.
Temperature
sensor faulty.
Temperature sensor cooling
The temperature sensor PCB is installed
inside a mesh. Turn the power off and cool
with a point cooler.
Replace
Main/Digital
PCB Assy.
Replace
temperature sensor
PCB.