Pioneer PDP-R03U Training Manual page 35

With both the media receiver and plasma units plugged in and the main power switch on,
pressing the Power on/ Standby switch on the remote or on the plasma display will start the
following power up sequence.
When the standby key is pressed the plasma display outputs +5v to the media receiver on the
SM Power line. This 5 volt line turns on the main power supply's 10v line. At the same time the
display also sends serial data on the RXD line to the media receivers main CPU (IC1). The RXD
data tells the media receivers CPU to power up and sends model information (PDP503PU or
PDP433PU). The main CPU then sends a conformation signal back to the display on the TXD line.
These serial data lines are the communication lines between the display and the receiver. Next
the main CPU sends a request to IC413 to perform Key IC data checks between the receiver and
the display through the SCL and SDA lines in the DVI cable. If the key ID data matches the
information stored in each EPROM, IC413 instructs the main CPU to turn on the DC to DC
converter. The DC to DC converter starts up and sends +5v back to the display on the CCKM line.
A additional +5v always on line SR UP is sent to the display from the media receivers power
supply. If anything in the startup procedure fails the media receiver will not power on. Key IC
data after power on is rechecked every 128 frames and if missing or the wrong Key data is
received the DVI output signal will stop and the main CPU will turn off the DC to DC converter.
Power On Procedure
35.