EN 24
5.
LX7500R
Diagnostic Software
servtest LX7500R sh 2, 041004
Y
QUARTZ TEST
Display shows
5859,375
±
175Hz can be
measurured on
(pin 18 of
µ
P 7107).
STOP button
pressed?
N
Y
Press
PLAY button.
Tact frequency
µ
P 7107
(divided 12MHz)
f
0
12 MHZ
Back to main menu.
The Quartz test allows a quick check of the oscillator of the
Combi board
µ
P 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
µ
P.
The test signal can best be measured on the junction
3072/3111
→
TEMPERATURE TEST
The temperature test is used to check the NTC resistors which
measure various temperatures to control the speed of the the
set fan.
NTC Front:
sensor for ambient temperature, located on
Display board.
NTC Amp(lifier): sensor for the temperature of the heatsink on
the Power Amplifier board.
The signals NTC_Front and NTC_Amp are compared with a
special algorithm and result in the control signal Set_Fan_Ctrl
which controls 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.
f
0
FRONT XX
Display shows
XX = value in ˚C
S
or
T
button
pressed?
N
Y
Y
Switch speed of set fan
to next/previous step.
Display shows
for 2s.
x= 1, 2, 3, 4
x= 1, 2, 3, 4
FAN SPE ED X
Press
PLAY button.
TEMPERATURE
TEST
N
N
Y
PLAY button
pressed?
Display shows
XX = value in ˚C
N
Y
PLAY button
pressed?
Back to main menu.
STOP button
pressed?
S
or
T
button
pressed?
N
Y
Y
Switch speed of set fan
to next/previous step.
Display shows
for 2s.
N
Back to main menu.
STOP button
pressed?
AMPLIFIER XX
FAN SPE ED X
Press
S
or
T
button
and select
QUARTZ
Press
S
or
T
button
and select
NTC
