Pioneer PDP-502MX Service Manual page 78

PDP-502MX
The state of
Lighting P.D. circuit
LED
circuit in operation
K751Hi VH UVP
D407
•
D439
K804Hi VRN OVP
K801Hi VRN UVP
K854Hi IC5V OVP
K3607Hi 12V OCP
D407
•
D437
K3704Hi RESET OCP
D3751 Anode is DRIVE STOP
High.
Diagnosis of malfunctions by power coming up sequence
Vsus 170V
Vadr 59V
Vcc
+14V/ + 8V/+12V/VF
STBY +5V/+12V
Power
off
Main
Power
on
Simple diagnosis using LEDs at Main Power Assy
The state of LEDs at Main Power Assy
After D205 lights up in red, D407 lights up. (D205 lights up in yellow in normal operation.)
After D305 is put out the light, D407 lights up. (D305 lights up in red in normal operation.)
After D355 is put out the light, D407 lights up. (D355 lights up in red in normal operation.)
D407 lights up at the stand-by mode.
After D205, D305 and D355 lights up normally, D407 lights up.
After D305 and D355 lights up normally, D407 lights up.
After D355 lights up normally, D407 lights up.
78
Diagnosis
Scan Module in normal
operation.
Drive section (drive control signals
& drive signal output elements) in
normal operation.
VRN D/D Conv. Block in normal
operation.
Output voltage of IC3606, 3607,
3608 are normal
Output voltage of IC3606, 3607,
3608 are abnormal.
P.D.
OVP: Over Voltage Protection, OCP: Over Current Protection, UVP: Under Voltage Protection
STBY LED
Approx. Approx.
ON (RED)
1.3 sec 0.4 sec
D205 (RED)
D355 (RED)
ON
STBY
D305 (RED)
mode
ON
Approx. 1.4 sec (AC100V)
Power
Approx. 0.04 sec (AC220V)
on
The power coming up sequence of power supply
Failure points
Y DRIVE Assy
IC5V D/D CONV. BLOCK
Y DRIVE Assy
VRN D/D CONV. BLOCK
Y DRIVE Assy
VRN D/D CONV. BLOCK
YDRIVE Assy
SUS_MSK BLOCK
Y DRIVE Assy
IC5V D/D CONV. BLOCK
Y DRIVE Assy
RESET BLOCK
DIGITAL VIDEO Assy
Vsus discharge
Vadr
0.02 sec
or more
D205 (YEL)
ON
Power
off
Estimated P.D. circuit in operation
VSUS UVP
VADR UVP
14V • 12V • ±8V UVP, B OVP, VF OVP
AC200V P.D.
VSUS OVP
VADR OVP
14V OVP
Estimated failure parts
IC851 • 852 • 853
IC801 • 803
IC801 • 802 • 803
R3717 • 3730
IC851 • 853
Pulse module
IC3604 • 3605 • 3609 • 3610
IC3611 • 3612 • 3613 • 3615 • 3601
• 3602 • 3603 • 3614
Q3708
IC2201 (IC23)
STBY Power
mode off
Main Power
off