Motor Controller Truth Table; Hall-Elements Input Signal Voltage Levels; Tray Control - Philips CDR775 Service Manual

Faultfinding Guide

Motor controller truth table

Input conditions conn 1006 pin
6 8 4
U+ U- V+
L M H
H M L
M M L
M M H
H M M
L M M
Hall-elements input signal voltage
levels
Input voltage
H
M
L
8.3.6

Tray Control

Description
The tray control consists of a TDA7073A power driver (7021)
controlled by the processor 7202 via pin 19 TRAYIN and pin 20
TRAYOUT. If pin 20 is low and pin 19 high, the TRAY+ signal
at pin 16 of 7021 is forced to +8V and the TRAY- signal at pin
13 of 7021 to GND : the tray will open. If pin 20 is high and pin
19 low, TRAY+ becomes GND and TRAY- becomes +8V : the
tray will close. If pin 19 and 20 of the processor have the same
value, TRAY+ and TRAY- will have the same value as well : the
tray stops moving.
Measurements
Keep procesor 7202 in reset by forcing pin 7 of connector 1208
to +5V. Connect a load of 15Ω, 7W between pin 3 and 4 of
connector 1002. Check the voltage over the load with TRAY+
(pin 3) as positive reference. Check also the levels of pins 19
and 20 of the processor.
U TRAY+,TRAY- = <100mV
Pin 20 = +5V
Pin 19 = +5V
Force pin 20 of the processor to ground, and check the
voltages.
U TRAY+,TRAY- = -6.5V( 10%
Pin 20 = +0V
Pin 19 = +5V
Force pin 19 of the processor to ground as well and check the
levels again.
U TRAY+,TRAY- = <100mV
Pin 20 = +0V
Pin 19 = +0V
Release pin 20 of the processor and check the levels.
U TRAY+,TRAY- = 6.5V( 10%
Pin 20 = +5V
Pin 19 = +0V
Release pin 19 of the processor and check the levels again:
U TRAY+,TRAY- = <100mV
Pin 20 = +5V
Pin 19 = +5V
7 3 2
V- W+ W- UCOIL
M M M
M M M
M H M
M L M
M L M
M H M
Level Tolerance
2.8 0.1
2.5 0.1
2.2 0.1
Outputs conn 1006
9 10 11
VCOIL WCOIL
6V 0V 0V
0V 6V 6V
0V 6V 0V
6V 0V 6V
0V 0V 6V
6V 6V 0V
Figure 8-26
Unit
V
V
V
CL96532086_056.eps
080999
Figure 8-27
CDR775 8.
Test points on driver
18 17
HALL_U HALL_V HALL_W
0V 5V
5V 0V
0V
5V
5V
0V
CL96532086_055.eps
GB 61
16
5V
0V
0V
5V
080999