servtest LX9000R sh 2, 040503
Y
QUARTZ TEST
Display shows
5859,375±175Hz can be
measurured
on
(pin 18 of µP).
STOP
button
pressed?
N
Y
Press
PLAY
button.
Tact frequency µP
(divided 12MHz)
f
0
12 MHZ
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.
FRONT XX
Display shows
XX = value in ˚C
Display shows
XX = value in ˚C
S or T
button
pressed?
N
YY
Switch speed of set fan
to next/previous step.
Display shows
for 2s.
x= 1, 2, 3, 4
x= 1, 2, 3, 4
x= 1, 2, 3, 4
x= 1, 2, 3, 4
FAN SPD X
Press
PLAY
button.
TEMPERATURE
TEST
NN
Y
PLAY
button
pressed?
Display shows
XX = value in ˚C
N
Y
PLAY
button
pressed?
Display shows
XX = value in ˚C
N
Y
PLAY
button
pressed?
N
Y
PLAY
button
pressed?
Back to main menu.
STOP
button
pressed?
S or T
button
pressed?
N
YY
Switch speed of set fan
to next/previous step.
Display shows
for 2s.
FAN SPD X
N
Back to main menu.
STOP
button
pressed?
S or T
button
pressed?
N
YY
Switch speed of set fan
to next/previous step.
Display shows
for 2s.
FAN SPD X
N
Back to main menu.
STOP
button
pressed?
S or T
button
pressed?
N
YY
Switch speed of set fan
to next/previous step.
Display shows
for 2s.
FAN SPD X
N
Back to main menu.
STOP
button
pressed?
SUPPLY XX
AMPLIFIER XX
TRAFO XX
Press
S or T
button
and select
QUARZ
Press
S or T
button
and select
NTC
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