Power On Sequence - Pioneer PDP-425CMX Service Manual

5

7.1.8 POWER ON SEQUENCE

KEY ASSY
Front key
MAIN ASSY
2
M+3.3V
KEY
Main UCOM
IC9501
M+3.3V
REG
M+7V → M+3.3V
Descriptions on operation
1 When the main power switch on the main unit is set to ON, M+7 V is supplied from the POWER SUPPLY Assy to the main
microcomputer to boot it.
2 A request to turn on the power is issued from a key on the main unit or remote control unit.
3 The STB_MUTE signal (STB+3.3 V, ON/OFF control) is output from the main microcomputer to the power supply.
4 STB+3.3 V is supplied from the power supply to the MD microcomputer to boot it.
5 The MD microcomputer issues the REQ_MD signal to the main microcomputer. (QS2 data read request)
6 After confirming the QS2 data read request (confirming SD or PD), the main microcomputer issues PON.
7 The MD microcomputer sends a PON echo back to the main microcomputer.
8 The MD microcomputer issues the RELAY signal to turn on the unit.
5
6
LED2 ASSY
Remote-control
sensor
U2401
COMM SLOT
IF ASSY
COMM SLOT
ASSY
2
REMI
M+3.3V
TXD
BUFF
IC8503
RXD
M+3.3V
BUFF
Q8503,Q8504
STB_MUTE
PDP-425CMX
6
7
DIGITAL ASSY
STB+3.3V
6
MD UCOM
7
IC3151
5
RELAY
REQ_MD
3
1
M+7.0V
7
8
POWER SUPPLY
ASSY
4
8
Power supply
UCOM
IC3151
163
8
A
B
C
D
E
F