Grundig CUC 7861 User manual
2GRUNDIG CUC 7861
Service Adju tment Cont’d. Trouble Shooting Guide
-Power Supply
1.4: Alignment
Line sharpness
Preparation
Select the convergence test pattern.
Contrast to maximum.
Set the brightness so that the black background
of the test pattern is just brightening.
Alignment Process
With the focus control adjust the horizontal lines
for maximum sharpness.
Attention: For measurements on the focusing
panel use only sufficiently insulated measuring
cables and test probes with adequate electric
strength (eg. 100:1).
1.5: Alignment
Tuner-AGC. Manual or Automatic.
Preparation
Manual:
Feed in a standard test pattern in the upper
range of the UHF band; the RF must be 1.5mV
(64dBmV, noise free picture) at least.
Info Centre --> Special Functions --> Service -->
Code 8500 --> Tuner-AGC --> Manual.
Automatic:
Info Centre --> Special Functions --> Service -->
Code 8500 --> Tuner-AGC --> Automatic.
AFC-Reference:
Info Centre --> Special Functions --> Service -->
Code 8500 --> AFC-Reference.
Tune to a local station on a channel as low
as possible at the desired programme position
with standard channel spacing without fine
tuning.
Not For Servicing.
Alignment Process
Manual:
With buttons - and + tune the TV station so that
noise just starts to appear in the picture. Then
tune in reverse direction until the picture
becomes noise free. Store with OK.
Automatic:
The control processor will set the optimum value
for the delayed gain control voltage. Activate
with button OK.
AFC-Reference:
On activation of AFC Reference Automatic a
rectified IF-voltage is measured at the AFC
output of the IF amplifier which is used on
station search as a comparative value for VCR-
RF playback (station identification “AV”) to
readjust the modulator drift. Activate with OK.
No function for the buttons - and +.
1.6: Alignment
Colour match.
Preparation
Call up the programme position of the desired
TV station.
Info Centre --> Special Functions --> Settings --
>Colour Match.
Alignment Process
Adjust with -and +buttons to make the signals
coincide. Store with OK.
1.7: Alignment
White balance
Preparation
Call up the White Balance menu via the Service
Programme Info Centre --> Special Functions --
> Service --> Code 8500.
Alignment Process
With - and +set the VG and VB values so that
the white rectangular area in the middle of the
picture becomes achromatic. Store with OK.
1.8: Alignment
Picture sharpness
Preparation
Call up the programme position of the desired
TV station.
Info Centre --> Picture Menu --> Sharpness.
Alignment Process
Change the value with the buttons - +.
1.9:Alignment
Picture geometry
Preparation
Info Centre --> Special Functions --> Service -->
Code 8500 --> Geometry.
For accurate adjustment of the picture a test
generator or standard test pattern should be
used. The integrated test pattern or grid pattern
may also be used.
Attention: Start always with the “V-Middle”
adjustment otherwise the other vertical deflec-
tion parameters would defy correct geometry
adjustment.
Alignment Process
Via the menu, select the geometry values for the
vertical deflection, then set the values for the
horizontal deflection.
Preparation
“V-Middle” adjustment with a colour test pattern:
select the “V-Middle” menu. The upper part of
the picture is coloured the lower part is black
and white.
Alignment Process
With the -or + button move the three broken
lines on the left and on the right of the indication
“V-Middle” upwards or downwards so that they
coincide with the line separating the coloured
part and B/W part of the picture.
Continue with the picture geometry adjustment
via the menu and store.
Preparation
“V-Middle” adjustment with a video generator,
eg. Grundig VG 1000.
Feed in the convergence test pattern with
standard colour bars via RF.
To store this adjustment move the bar to
“Terminate with Store” and confirm with OK.
Alignment Process
With the -or +button change the setting so that
the G-Y vector (orange area in the centre of the
picture) is just covered.
Continue with the picture geometry adjustment
via the menu and store.
Preparation
The picture geometry is set to the last stored
value whenever the receiver is switched on.
Reset:
Under the menu item “Reset” an average data
set from the ROM IC860 is stored. After
inadvertent readjustment during servicing, these
basic values can be re-loaded at any time. For
this, move the bar to “Reset”. Press the OK
button. By pressing the “AUX” button the picture
geometry is set according to the “Reset” values.
With the i button return to the normal menu.
Control Keyboard
Diagram
Interference Elimination Diagram
5GRUNDIG CUC 7861
CRT Diagram
Control Unit Diagram Velocity Diagram
Waveform
6GRUNDIG CUC 7861
Socket Diagram
7GRUNDIG CUC 7861
Colour Decoder
Sync. Diagram
8GRUNDIG CUC 7861
DSP Diagram
9GRUNDIG CUC 7861
Di play Control Unit with Videotext Diagram
10GRUNDIG CUC 7861
AF Output Diagram “A”
11GRUNDIG CUC 7861
AF Output Diagram “B”
14GRUNDIG CUC 7861
Tuner Diagram
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