Service Hints - Philips LX3950W/01 Service Manual

1.3. Service hints, faultfinding and alignments
1.3.1 Measurement setup
wireless transmitter
test circuit
F150
DUT
L + R
e.g. PM2534
F114
AC-mV meter
e.g. FAM
from R&S
OUTPUT MEASURING
ANALYSER
e.g. PM5110
Wireless Transmitter functional check and adjustment table Audio AD905W (LX3750W) versions
Measurement
Powersupply check ground testpoint Scope / Voltmeter
F119 +12V ± 0.5V
F124 + 8.35V ± 0.25V
F126 + 5V ± 0.25V
DC Check F116 F145 + 2.52V ± 0.2V
F144 + 2.52V ± 0.2V
F147 + 4.2V ± 0.3V
F149 + 4.2V ± 0.3V
picture DUT:
LF input signal
Input and
L = 400Hz;
input level testpoint Measurement
R = 400Hz,
ground
via
F117 410 mV L
F130
F118 410mV R
F117 410 mV L
F131
F118 410mV R
F117 410 mV L F145
F118 410mV R F144
F116
F117 410 mV L
F147
F118 410mV R
F117 410 mV L
F149
F118 410mV R
F117 2100 mV L
F149
F118 2100 mV R
Check RF output signal
LF input signal
L = 400Hz;
input level Input ground channel
R = 400Hz,
via
F117 0 mV L
F116 4
F118 0 mV R
Alignment of the modulation level *
Method 1
LF input signal Connect RF
L = 400Hz; Modulation
input level input ground
R = 400Hz, Analyzer
via to testpoint
F117 410 mV L
F116 F114
F118 410 mV R
Method 2
LF input signal
Connect AC mV
L = 400Hz;
input level input ground meter
R = 400Hz,
to testpoint
via
F117 410 mV L
F116 F150
F118 410 mV R
* or Method 1 or Method 2 to be applied
Figure 1-4 Table AV transmitter
11-2
CL36532008_019.eps
150403
AC Voltmeter Frequency counter
23.4375 kHz ± 10 Hz
46.875 kHz ± 20 Hz
210 mV ± 20 mV
210 mV ± 20 mV
200 mV ± 20 mV
205 mV ± 20 mV
380 mV ± 40 mV
Measurement
Output signal Frequency counter
RF ground
for EUR and UK
864.5 ± 0.025 MHz
F115 F114 version
for USA version
915.3 ± 0.025 MHz
Measurement RF Modulation
Align
ground Analyser deviation
F115 3179 50 kHz ± 3 Hz
Measurement
Align AC mV meter
ground
F116 3179 80mV rms (= 230mV pp)
wireless receiver test circuit
To RX input
DUT
68 E
LF Voltmeter
e.g. PM2534
CL36532008_020.eps
170403
Alignment of the receiver EUR version
RF input
signal,
modulation = RF carrier
Input signal
50 kHz via frequency
adaptation
network*
F748 863.3 MHz 1 mV rms
F748 863.3 MHz 250 µV rms
F748 863.3 MHz 250 µV rms
F748 863.3 MHz 10 µV rms
Version
F748 863.3 MHz 10 µV rms
Alignment of the receiver USA version
RF input
signal,
modulation = RF carrier
Input signal
50 kHz via frequency
adaptation
network*
F748 914.1 MHz 1 mV rms
F748 914.1 MHz 250 µV rms
F748 914.1 MHz 250 µV rms
F748 914.1 MHz 10 µV rms
F748 914.1 MHz 10 µV rms
* e.g. SMT02 from Rohde & Schwarz
11-2
WirelessReceiver functional check and adjustment table Audio AD905W (LX3750W) versions
Powersupply
check
DC Check
Functional check
picture: receiver test circuit:
RF input
signal,
channel
modulation = RF carrier
Input signal switch
50 kHz via frequency
select
adaptation
network*
F748 863.3 MHz 1 mV rms channel 1
F748 914.1 MHz 1 mV rms channel 1
channel
Testpoints
switch Alignment Align
grounded to F744
select
FM Detector
F724 & F725 channel 1 1710
coil
Remove
groundin gs F724 &
F725
Sliding stereo
channel 1 3743
signal
Sliding stereo reduce 3743
channel 1
signal slowly
Tuned/Muted
channel 1 3741
level
Tuned/Muted reduce 3741
channel 1
level slowly
channel
Testpoints
switch Alignment Align
grounded to F744
select
FM Detector
F724 & F725 channel 1 1710
coil
Remove
groundin gs F724 &
F725
Sliding stereo
channel 1 3743
signal
Sliding stereo reduce 3743
channel 1
signal slowly
Tuned/Muted
channel 1 3741
level
Tuned/Muted reduce 3741
channel 1
level slowly
Figure 1-5 Table AV receiver
Measurement
ground testpoint Scope / Voltmeter
F702 +10V ± 0.1V
F740 + 5.2V ± 0.5V
F705 + 8V ± 0.5V
F701
F707 + 8V ± 0.5V
F708 +3.6V ± 0.2V
F709 +7.75V ± 0.5V
F744 F740 + 5.2V ± 0.2V
F712 + 4.1V ± 0.3V
F701
F713 + 4.1V ± 0.3V
Output signal Voltmeter version
for EUR and UK
F728 LF output
version
F728 LF output for USA version
Output signal Voltmeter version
for EUR and UK
F728 LF max output
version
for EUR and UK
F747 >3 V DC
version
between 0.2 and for EUR and UK
F747
3 V version
for EUR and UK
F724 >2.5 V DC
version
for EUR and UK
F724 < 1 V
version
Output signal Voltmeter version
F728 LF max output for USA version
F747 >3 V DC for USA version
between 0.2 and
F747 for USA version
3 V
F724 >2.5 V DC for USA version
F724 < 1 V for USA version
CL 36532008_088.eps
220403