Philips LX9000R Service Manual page 26

EN 26 5. LX9000R
QUARTZ TEST
Press
S or T button
QUARZ
and select
Press PLAY button.
Y
Tact frequency µP
(divided 12MHz)
Display shows
12 MHZ
5859,375±175Hz can be
measurured on
(pin 18 of µP).
f
0
STOP button
pressed?
Y
Back to main menu.
The Quartz test allows a quick check of the oscillator of the
Front µP without any influence to the oscillator circuitry by the
test equipment.
The factory can check if the correct quartz has been
assembled.
A 50% duty pulse of the divided oscillator frequency is put on
pin 18 of the µP (MDM_SCL).
To avoid dismantling of the front cabinet the test signal can best
be measured on pin 9 of 1802, located on the MDM board.
TEMPERATURE TEST
The temperature test is used to check the NTC resistors which
measure various temperatures to control the speed of the basic
engine fan and the set fan.
NTC Front: sensor for ambient temperature, located on
Key board left.
Controls the fan of the basic engine.
NTC Supply: sensor for the temperature of the heatsink on
the Power Secondary board.
NTC Amp(lifier): sensor for the temperature of the heatsink on
the Power Amplifier board.
NTC Trafo: sensor for the temperature of the main
transformer.
The signals NTC Supply, NTC Amp and NTC Trafo are
compared with a special algorithm and result in the control
signals SetFan1 and SetFan2 which control the speed of the
set fan.
In each test step of the temperature test the speed of the set
fan can be set in four steps.
Diagnostic Software
TEMPERATURE
TEST
N
Press
S or T button
NTC
and select
Press PLAY button.
Display shows
FRONT XX
XX = value in ˚C
PLAY button N
STOP button
pressed? pressed?
Y
Back to main menu.
Display shows
SUPPLY XX
XX = value in ˚C
N
PLAY button STOP button
pressed? pressed?
Y
Back to main menu.
Display shows
AMPLIFIER XX
XX = value in ˚C
N
PLAY button STOP button
pressed?
pressed?
Y
Back to main menu.
Display shows
TRAFO XX
XX = value in ˚C
N
PLAY button STOP button
pressed?
pressed?
Y
Back to main menu.
N
S or T button
pressed?
Y Y
Switch speed of set fan
to next/previous step.
Display shows
FAN SPD X
for 2s.
x= 1, 2, 3, 4
N
S or T button
pressed?
Y Y
Switch speed of set fan
to next/previous step.
Display shows
FAN SPD X
for 2s.
x= 1, 2, 3, 4
N
S or T button
pressed?
Y Y
Switch speed of set fan
to next/previous step.
Display shows
FAN SPD X
for 2s.
x= 1, 2, 3, 4
N
S or T button
pressed?
Y Y
Switch speed of set fan
to next/previous step.
Display shows
FAN SPD X
for 2s.
x= 1, 2, 3, 4
servtest LX9000R sh 2, 040503
N
N
N
N