Abgleich / Adjustment Procedures
GV 54…, GV 56 …, SE 5106…
3 - 6
GRUNDIG Service
2.2 Family Board – Frontend (FE)
Test equipment / aids: Oscilloscope (>50MHz) with 10:1 Test Probe, Voltmeter, Colour Generator with Stereo Coder.
Service work after changing the …
… IC7520: Adjustment no. 1, 2, 3, 4
… Tuner: Adjustment no. 2, 5
Adjustment
Preparation
Adjustment Procedure
1. Vision Demodula-
tor
F1030
(AFC-ADJ)
2. Tuner AGC
voltage
R3540
(AGC-ADJ)
3. Chroma Amplitude,
R3613
(CHR-ADJ)
4. Crosstalk
5. ATS Adjustment
Feed in a video IF signal (38.875MHz, 90…100dB
µ
V, standard
test pattern) at MP
87
.
Voltmeter: ............................................................ MP
86
EE operation
Solder a 4.7pF capacitor to MP
87
. Connect the
oscilloscope to the free contact of the capacitor.
Feed in a standard test pattern without audio modulation
(UHF range, Ch 26, 67dB
µ
V aerial signal) to the warmed
up VCR.
EE operation
Feed in a standard test pattern without audio modulation
(UHF range, Ch 26, 67dB
µ
V aerial signal) to the warmed
up VCR.
Oscilloscope: ....................................................... MP
83
EE operation
Feed in a standard test pattern with "Stereo" sound modulation.
Oscilloscope: ....................................................... MP
82
HF recording
Call up the Service Function with the remote control:
– Press the "CODE" button.
"
CODE -- -- -- --
" is indicated in the display.
– Enter
4 9 3 4
in this order and confirm with button
G
.
Feed in a standard test pattern (UHF range, Ch 26,
50dB
µ
V aerial signal).
HF recording
Call up the Service Function with the remote control:
– Press the "CODE" button.
"
CODE -- -- -- --
" is indicated in the display.
– Enter
4 9 3 4
in this order and confirm with button
G
.
With F1030
(AFC-ADJ)
set the voltage to 2.5V
±
0.1V.
With R3540
(AGC-ADJ)
adjust the amplitude to 100mV
pp
.
Remove the 4.7pF capacitor.
With R3613
(CHR-ADJ)
set the burst amplitude to the level
of the sync pulses.
Set the crosstalk to minimum as follows:
Coarse: remote control key
1
= "
A1
",
2
= "
A2
"
Fine: remote control key
3
= "
A3
",
4
= "
A4
"
Terminate the alignment procedure by pressing button
H
.
Terminate the Service Function by pressing button
A
or by
disconnecting the VCR from the mains.
Press button
7
. "
A7
" is indicated on the right of the display.
Terminate the alignment procedure by pressing button
H
.
Terminate the Service Function by pressing button
A
or by
disconnecting the VCR from the mains.
2.3 Family Board – IN/OUT (IO)
Test equipment / aids: Oscilloscope with 10:1 Test Probe, Colour Generator with HF and video output.
Service work after changing the Family Board, Family Board II, IC7500 (VS) or IC7520 (FE): Adjustment no.1
Adjustment
Preparation
Adjustment Procedure
1. "Follow TV"
Amplitude,
R3863
(FMA)
With R3863
(FMA)
adjust the signal according to the diagrams
below.
not correct
correct
10ms/cm
Terminate the alignment procedure by pressing button
H
.
Terminate the Service Function by pressing button
A
or by
disconnecting the VCR from the mains.
Feed in a white test pattern (100% white, aerial signal
>60dB
µ
V) at the aerial input.
Feed in a white test pattern (100% white, 1V
pp
, 0.3V sync /
0.7V CVS component) at the EURO-AV1socket (same
colour generator as that of the aerial input).
Oscilloscope: ....................................................... MP
34
HF recording
Call up the Service Function with the remote control:
– Press the "CODE" button.
"
CODE -- -- -- --
" is indicated in the display.
– Enter
4 9 3 4
in this order and confirm with button
G
.
– Press button
8
. "
A8
" is indicated on the right of the
display.