Pioneer PDP-433PU Service Manual page 84

1
Block diagram of the Power supply section
SW POWER SUPPLY MODULE
A
AC IN
100 - 240V
Power Supply
B
Supplementary information
1. Power on/off switch for the large-signal system (SW102)
Function: Only the power for the small-signal system
(15V, 12V, 6.5V, 13.5V, and -9V) is on, and the
power for the large-signal system (VSUS, VADR) is
C
off.
Usage:
Use when only an operational check for the small-
signal system is required.
Supplementary information:
When this switch is to be used, the wires of pin 5
(DIG, ADR, and PD) of the P2 connector of the
power-supply module should be disconnected to
prevent the PD circuit from operating. To turn the
power of the large-signal system off without using this
switch, operation from an external PC through
RS-232C commands "DRF" is basically required. In
this case, the above procedure is not required, as the
PD circuit is muted by software.
D
How to turn on the power with a command sent via
RS-232C communication when the large signal
system's power is off
1 Check that the unit is in Standby mode.
2 Transmit the RS-232C command "DRF."
3 Turn on the power using the remote control unit, side keys,
or the command "PON."
Note: Once the power is turned off, the setting of the large
signal system power returns to ON.
If you wish to turn on the power when the large signal
system's power is off, transmit the DRF command each
E
time.
2. 200V AC power-down switch (SW101)
Function: While 200V AC voltage is applied, operation of the
PD circuit is turned on and off (ON when the switch is
set to 100V AC, and OFF when the switch is set to
200V AC).
Setting:
For the PU model only, the switch is set to 100V,
and for other models, it is set to 200V.
F
84
1
2
+B395V
Power Factor VSUS DC/DC
Control Converter
VADR DC/DC
ST-BY
Converter
6.5V DC/DC
STB5V
Converter
(6.5V, 13.5V, -9V)
15V DC/DC
Converter
(15V, 12V)
2
3
Y DRIVE ASSY
VSUS
215V
VADR
61V
13.5V
X DRIVE ASSY
-9V
12V
DIGITAL VIDEO ASSY
3. Temperature compensation of the VSUS voltage for
the drive system
Function: Control the power supply voltage mentioned above
according to temperature. (Temperature compensation
works so that the voltage is lowered on the lower-
temperature side, and is raised on the higher-
temperature side.)
Purpose: To improve the yield by compensating the temperature
characteristics of the panel.
Supplementary information:
For this model, temperature compensation is perform-
ed only for the VSUS voltage, and not for the VOFS
voltage, and it is controlled by software.
4. When a fuse blows
• If a fuse blows, never turn the power on again only after
replacing the fuse. (In most cases, the fuse itself did not have
any problem. So as long as factors of overcurrent have not been
removed, chances of destruction increase every time the power
is turned on. In the worst case, about a dozen parts may be
destroyed.)
• Generally, the whole power-supply module assembly must be
replaced.
5. Voltage adjustment of the panel drive
As this model employs the electronic VR system for the VSUS
and VOFS voltages, and as the voltage-adjustment data are stored
in the DIGITAL assembly, voltage adjustment of the panel drive
is not necessary when the power-supply modules are changed.
(For VADR, VH, and VRN, adjustments with semifixed VR
controls are necessary.)
For this model, as the power-supply block has been developed
and designed by an outside vendor, at the point you know which
module is a cause of failure (through diagnosis described
elsewhere in this manual), change the corresponding modules, and
do not diagnose or repair the module.
Similarly, the switches and the semifixed VRs inside the power-
supply module must not be adjusted without a special reason.
PDP-433PU
3
4
VOFS
VOFS DC/DC
-45V
Converter
VH DC/DC VH
130V
Converter
IC5V, VF12V
IC5V
DC/DC
VF12V
Converter
VRN DC/DC VRN
–280V
Converter
5.0V
15V DC/DC
Converter 3.3V
(5V, 3.3V, 2.5V)
2.5V
4