Pioneer PDP-502MX Service Manual page 77

The state of
Lighting P.D. circuit
LED
circuit in operation
D408 Anode is VADR UVP
D407
High/ High
between base &
emitter of Q416
D408 Anode is 14V UVP
High/ High
between base &
emitter of Q418
D408 Anode is 12V UVP
High/ High
between base &
emitter of Q421
D408 Anode is 8V UVP
High/ High
between base &
emitter of Q420
D408 Anode is –8V UVP
High/ High
between base &
emitter of Q435
D405 Anode is B OVP
High
High between AC200V P.D.
base & emitter
of Q111
D448 Anode is VF OVP
High.
TP555 Hi
5V OVP
D407
•
TP556 Hi 5V UVP
D443
TP604 Hi 3.3V OVP
TP603 Hi 3.3V UVP
D4501 Anode is High. AUDIO P.D.
D3457 Anode is 12V OCP
D407
High.
•
D441
K706Hi VOFS OVP
D407
•
D439
K705Hi VOFS UVP
K754Hi VH OVP
K751Hi VH UVP
Diagnosis
When CN205 is disconnected,
P.D. occurs, and even when
RCC Control (B) Assy and OTL
Control (B) Assy are replaced,
P.D occurs.
When CN205 is disconnected,
P.D. does not occur.
When CN306 & 354 are
disconnected, P.D. occurs.
When CN306 is disconnected,
P.D. does not occur.
When CN354 is disconnected,
P.D. does not occur.
When VF D/D Converter Assy is
replaced, P.D. does not occur.
When CN355 is disconnected,
P.D. occurs.
When CN356 is disconnected,
P.D. does not occur.
When CN306 is disconnected,
P.D. occurs.
When CN306 is disconnected,
P.D. does not occur.
When CN306 is disconnected,
P.D. occurs.
When CN306 is disconnected,
P.D. does not occur.
AC power input is appropriate.
Output voltage of IC3456, 3457,
3458 are normal
Output voltage of IC3456, 3457,
3458 are abnormal.
Drive section (drive control signals
& drive signal output elements) in
normal operation.
VOFS D/D Conv. Block in normal
operation
Drive section (drive control signals
& drive signal output elements) in
normal operation.
VH D/D Conv.Block in normal
operation
Failure points
MAIN POWER Assy IC301 • 302 • Q302
CABLE Assy
MAIN POWER Assy RCC Control (C) Assy • OTL
14V D/D CONV. BLOCK Control (C) Assy • IC351 • 352
ANALOG VIDEO Assy
Y DRIVE Assy IC852
IC5V D/D CONV. BLOCK
VF DD CONV. Assy IC503
MAIN POWER Assy RCC Control (C) Assy • OTL
12V D/D CONV. BLOCK Control (C) Assy • IC351 • 352
IC551 • 601 • Q554 • 555 • 604 • 605
DIGITAL VIDEO Assy
D/D CONV. BLOCK
MAIN POWER Assy
RCC Control (C) Assy • OTL
8V D/D CONV. BLOCK Control (C) Assy • IC351 • 352
ANALOG VIDEO Assy
MAIN POWER Assy RCC Control (C) Assy • OTL
–8V D/D CONV. BLOCK Control (C) Assy • IC351 • 352 •
D373
ANALOG VIDEO Assy
MAIN POWER Assy IC131
PFC BLOCK
MAIN POWER Assy IC111 • 112 • 113 • T111
STB BLOCK
VF D/D CONV.Assy IC502 • 503 • 504
DIGITAL VIDEO Assy IC551
5V D/D CONV.BLOCK
DIGITAL VIDEO Assy IC601
3.3V D/D CONV. BLOCK
AUDIO Assy IC4502 • C4520 • 4522
Pulse module
IC3454 • 3455 • 3459 • 3460
IC3461 • 3462 • 3463 • 3465 • 3451
• 3452 • 3453 • 3464
Y DRIVE Assy IC702 • 704
VOFS D/D CONV. BLOCK
Y DRIVE Assy IC701 • 702 • 704
VOFS D/D CONV. BLOCK
Y DRIVE Assy R3717 • 3730
SUS_MSK BLOCK
Y DRIVE Assy IC751 • 752
VH D/D CONV. BLOCK
Y DRIVE Assy IC751 • 752 • 755
VH D/D CONV. BLOCK
SCAN MODULE SCAN IC
PDP-502MX
Estimated failure parts
77