Grundig GV 440 NIC Servicehandbuch Seite 91

GV44..., GV45..., GV46...
2.4 Family Board – Video (VS)
Test Equipment: Oscilloscope, 10:1 Test Probe, Frequency Counter, Stabilized Power Supply, Colour Generator, Test Cassette.
Service work after replacing the Family Board: Adjustment no. 3, 5
Adjustment
1. EE-Level / Sync- Feed in a white test pattern (100% white, 1V
Level Control, component, 0.7V CVS component).
R3635 (EE) Oscilloscope: ...................................................... MP
AV recording.
2.1 Frequency Unsolder C2605.
Deviation Sync Frequency counter: ............................................. MP
Value, R3752 AV recording.
(SV)
Frequency counter: ............................................. MP
2.2 White Value, Oscilloscope:
R3755 (WV)
AV recording.
Mark the white value of the CVS signal with the unused
beam B of the oscilloscope.
Unsolder C2605.
Power Supply: Connect positive (0V) to IC7510-(42) via
3. Video Record
Oscilloscope: ............................. Head Amplifier, MP
Voltage, R3707 AV recording.
(YWV)
4. Playback Amplitu- Oscilloscope: ...................................................... MP
de, R3768 (PBA) Play back a white test pattern (self-made recording).
5. FM-Reference Playback
Level Adjustment Call up the service function:
for Automatic – Press the
(" CODE – – – – " is indicated in the display).
Contour Control
– Enter the code number
button (" SERV " is indicated in the display).
2.5 Family Board – Chroma (VS)
Test Equipment: Oscilloscope with 10:1 Test Probe.
Service work after replacing the Family Board: –
Adjustment
1. Chroma Record Short-circuit C2552.
Voltage, R3693 Feed in a colour bar test pattern.
(CWV) Oscilloscope: ............................. Head Amplifier, MP
Record.
2. 627kHz Comb Oscilloscope: ...................................................... MP
Filter, R3918 (CF) Trigger: ................................................. HI pulse 1506-3.
Play back a self-made recording (red test signal).
GRUNDIG Service-Technik
Preparation
Channel A: IC7510-(42),
Channel B: Marking beam
Trigger: IC7510-(33), switch
oscilloscope to DC.
a diode; cathode of the diode to pin 42.
Connect negative to chassis.
Z
button on the remote control handset
4 9 3 4
and press the
Preparation
, 0.3V sync Set amplitude with R3635 (EE) to 0.5V
PP
31
Set frequency counter with R3752 (SV) to 3.8MHz.
32
Solder in C2605.
32
Increase the voltage of the power supply slowly, till both
beams coincide.
Set frequency counter to 4.85MHz with R3755 (WV).
Solder in C2605.
1 Set FM signal with R3707 (YWV) to 0.22V
33
Set amplitude with R3768 (PBA) to 2V
Press the button
and on the right " A1 ". On successful adjustment the video
recorder switches to Pause
To cancel the service function: Press the "Standby" button
O
or disconnect the recorder from the mains.
Set amplitude with R3693 (CWV) to 55mV
Remove the short circuit.
1
41
With R3918 (CF) set the signal as shown in the oscillo–
grams below.
µ
200 s/cm
Abgleichvorschriften / Adjustment Procedures
Adjustment Procedure
.
PP
.
PP
.
PP
1 . The display shows on the left " PICT "
Adjustment Procedure
.
PP
Incorrect
CORRECT
Incorrect
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