Abgleich / Adjustment Procedures
GV 54…, GV 56 …, SE 5106…
3 - 8
GRUNDIG Service
4. Family Board II (OKV++G) – Video/Chroma (VS)
Test equipment / aids: Oscilloscope with 10:1 Test Probe, Frequency Counter, Digital Voltmeter, Colour Generator, Test Cassette
Service work after changing the …
… Family Board II: 2.3 Family Board – IN/OUT: Adjustment no. 1
… Family Board, headwheel or IC7600: Adjustment no. 2
… IC7500: Adjustment no. 1, 3
Adjustment
Preparation
Adjustment Procedure
Frequency counter: ............................................. MP
32
AV recording (do not feed in a signal)
Play back the test cassette
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
.
Connect MP
33
to ground.
Play back a100% white test pattern (recording made on the
machine).
Measure the voltage at MP
34
with the digital voltmeter
and note it down.
Digital voltmeter: ................................................. MP
36
Digital voltmeter: ................................................. MP
35
Feed in and record a PAL white test pattern of 100%
saturation.
Measure the FM signal at MP
52
with an oscilloscope and
note it down.
Connect MP
32
to ground.
Feed in and record a PAL red raster test pattern.
Oscilloscope: ...................................................... MP
53
1. Sync Level,
R3488
(SW)
2. FM Reference
Level for "ACC
(Automatic Contour
Control) plus Studio
Quality"
3. S-VHS-PB
Detection
Reference Level
– S-VHS
R3409
(REFS)
– VHS
R3481
(REFV)
4. PAL Chroma
Writing Current,
R3363
(CAP)
5. Teletext "DOS" (OVPTG / VT)
Test equipment / aids: Two-channel Oscilloscope with 1:1 Test Probes.
Service work after changing the components F1001/C2011: Adjustment no. 1
Oscilloscope, channel 1: ................ IC7140-(10), MP
12
Channel 2: ........................................ IC7140-(7), MP
11
Trigger: .................................... channel 2, negative edge
Feed in a HF-signal (PAL) / Record or EE-mode without
Teletext.
With F1001 set the time interval between the middle of the
pulse H/2-SYNC (IC7140-(7)) and the trailing edge of
SYNC (IC7140-(10)) to
∆
t = 32
µ
s
±
10
µ
s.
64
µ
s
∆
t
IC7140-(7)
IC7140-(10)
Adjustment
Preparation
Adjustment Procedure
1. H/2-Sync
Adjustment, F1001
With R3488
(SW)
adjust the frequency to 3.8MHz.
Press button
1
. "
A1
" is indicated on the right of the display.
On successful completion of the adjustment the VCR
switches to still.
Terminate the Service Function by pressing button
A
or by
disconnecting the VCR from the mains.
With R3409
(REFS)
adjust the voltage so that its level is
0.21V higher than that measured at MP
34
.
With R3481
(REFV)
adjust the voltage so that its level is
0.34V higher than that measured at MP
34
.
Remove the ground connection from MP
33
.
With R3363
(CAP)
set the chroma signal to 75%
of the FM
signal (MP
52
) einstellen.
Remove the ground connection from MP
32
.
