Prescriptions d'alignement / Adjustment Procedures
3 - 6
GRUNDIG Service
Call up the Service Function with the remote control handset:
– Press the button "CODE", enter the code number
4 9 3 4
and press the
G
button.
– Press the button "CODE", enter the code number
4 9 5 0
and press the
G
button.
Frequency Counter: ........................................... 1101-(1)
2.4 Family Board – Standard Sound / Audio Linear (AL)
Test equipment / aids: AF Millivoltmeter, AF Generator, Video Cassette of reputable brand.
Service work after replacing the Family Board, the RP-Head or the Erase-Head: Adjustment no. 1.1, 3
Adjustment
Preparation
Adjustment Procedure
With F5603
(Erase Oscillator)
set the reading on the frequency
counter to 70kHz
±
10kHz.
Set the voltage drop across R3600 with R3618
(BIAS)
to
15mV
rms
.
Check the frequency response.
The voltage ratio of 400Hz to 8kHz must not be higher than
1:0.7 or 0.7:1 (
±
3dB). If the voltage ratio exceeds these
limits, the bias must be altered:
To increase the playback voltage at 8kHz: Reduce "BIAS".
To reduce the playback voltage at 8kHz: Increase "BIAS".
Remove the 270
Ω
resistor between IC7601-(10) and
ground.
With F5604
(Dub Oscillator)
set the reading on the frequency
counter to 70kHz
±
10kHz.
Set output voltage with R3606
(PB-Lev.)
to 0.5V
rms
±
50mV.
Frequency counter: ............................................ 1918-(1)
Record
AF millivoltmeter: ................................................... R3600
Record.
– Connect IC7601-(10) via 270
Ω
resistor to ground.
– Feed in a CCVS signal via EURO-AV1 socket, contact 20.
– Feed an audio signal of 200mV
rms
(480mV
PP
) from the AF
generator to the EURO-AV1 socket, contact 2 or 6.
– Make a recording of 400Hz and 8kHz each of 1 min at
least. Afterwards play back these recordings.
– Connect an AF millivoltmeter (oscilloscope) to EURO-AV1
socket, contact 1 or 3.
Frequency counter: ............................................ 1919-(2)
Record
AF generator (1kHz / 0.7V
rms
):
................................... EURO-AV1 socket, contact 2 or 6
AF millivoltmeter: ....... EURO-AV1 socket, contact 1 or 3
Record (Normal Play).
Play back this recording.
1. Erase Frequency,
F5603
1.1 Bias, R3618
1.2 Frequency
Response Test
2. Full Track Erase
Frequency, L5604
(Only for sets with
dubbing)
3. Playback Level,
R3606
3. Family Board II (OSIO) – OSD
Test equipment: Frequency Counter
Service work after replacing the Family Board II: –
Adjustment
Preparation
Adjustment Procedure
1. OSD, C2820
With C2820 set the reading on the frequency counter to
17,34475MHz.
Frequency Counter: ........................................ IC7820-(3)
Info-mode
4. Keyboard Control Unit (ODCG…)
Test equipment: Frequency Counter
Service work after replacing the Keyboard Control Unit: –
Adjustment
Preparation
Adjustment Procedure
The period is set with C2005
(CLOCK ADJ.)
to 488.281,25ns
±
0,715ns by the manufacturer.
1. Clock, C2005
