Grundig CUC 2030 N Service Manual page 28

Abgleich / Alignment
Alignment
GB
Note:
The CUC 20xx chassis are either fitted with TDA 8843/8375 or TDA 8843-N2/8844-N2. Type TDA 8843-N2/8844-N2 has a PLL demodulator
integrated in it so that the AFC adjustment in the Service Menu is not necessary.
Attention!
1. After any repair or replacement of NVM (IC82005) check whether the NTSC 3.58MHz quartz is fitted. If it is not, the dialog line "NTSC 3,6" in the
Service Menu must be set to "off".
Button " " –> "OK" –> "SERVICE" –> "OK" –> Service Code "8500" –> NTSC 3,6 "off" and in dialog line "End" store the setting "with mem.".
2. When no SAT Receiver (SNR 105 microSAT) is connected to the AV1 socket, SAT in the Service Menu is to be set to "off".
Button " " –> "OK" –> "SERVICE" –> "OK", select dialog line "SAT" and switch to "off".
All adjustment controls not mentioned in this description are pre-set at the factory and must not be re-adjusted in the case of repairs.
1. Chassis Board
Measuring instruments: Dual-channel oscilloscope, 10:1 test probe, digital voltmeter, colour video generator, spectrum analyser or RF millivoltmeter
Service works after replacement or repair of the following modules:
- Power supply: alignment 1.1
- Tuner: alignment 1.2, 1.3 / 1.4
- NVM IC82005: alignment 1.2 ...1.8, 2.1, 2.2, 3.1, 3.3
- Horizontal deflection: alignment 1.9
Alignment
1.1 +A voltage This voltage must be checked and re-adjusted if necessary
after every repair and before every alignment.
Brightness: Minimum
Digital voltmeter: Cathode D61016
Spectrum analyser or RF millivoltmeter symmetrical to
1.2 Tuner AGC
tuner contact 10, 11.
Feed in a standard test pattern or generator via the aerial,
70...80dBµV.
Call up the dialog line "AGC" via " " (DIALOG CENTER) –>
"OK" –> SERVICE –> "OK" –> Service Code "8500".
1.3 AFC Reference Feed in a generator test pattern with vision carrier 38.9MHz,
ca. 120mV to tuner contact 10, 11.
only VST Tuner
Call up the dialog line "AFC" via " " (DIALOG CENTER) –>
"OK" –> SERVICE –> "OK" –> Service Code "8500".
1.4 AFC Reference Feed in a standard test pattern with standardized channel
spacing, band 1 (channel 2...4) without finetuning.
only PLL-Tuner
Call up the dialog line "AFC" via " " (DIALOG CENTER) –>
No adjustment "OK" –> SERVICE –> "OK" –> Service Code "8500".
necessary with
TDA 8843-N2
TDA 8844-N2
1.5 OSD Call up the dialog line "OSD" via " " (DIALOG CENTER) –>
"OK" –> SERVICE –> "OK" –> Service Code "8500".
1.6 Tube Call up the dialog line "Tube" via " " (DIALOG CENTER) –>
(Type of picture "OK" –> SERVICE –> "OK" –> Service Code "8500".
tube)
2 - 4
Preparations
CUC 2030 N / 2050 N / 2058 N / 2059 N / 2080 N
Alignment Process
Adjust R60037 or R61313 acc. to the table (page 3-16) on
the power supply circuit diagram.
Adjust 102dBµV (360mV ) with button
pp
Alternatively, without using a spectrum analyser or RF
millivoltmeter, adjust the picture with button
noise just appears on the screen. Then reset until the
picture is again free of noise.
Dialog line "End", terminate "with mem".
Activate the setting with "OK".
Internal adjustment of the PLL demodulator is carried out.
If an arrow is displayed beside the text after adjustment,
re-adjust the AFC with demodulator filter F33025 until the
arrows disappear. The arrow on the left or right of the AFC
value in the menu indicates the sense of rotation for
adjusting the filter.
Arrow on the right, core of the filter turned in too far.
Arrow on the left, core of the filter turned out too far.
Repeat this adjustment with "OK".
Dialog line "End", terminate "with mem.".
Activate the setting with "OK".
Internal adjustment of the PLL demodulator is carried out.
If an arrow is displayed beside the text after adjustment,
re-adjust the AFC with demodulator filter F33025 until the
arrows disappear. The arrow on the left or right of the AFC
value in the menu indicates the sense of rotation for
adjusting the filter.
Arrow on the right, core of the filter turned in too far.
Arrow on the left, core of the filter turned out too far.
Repeat this adjustment with "OK".
Dialog line "End", terminate "with mem.".
With button or position the menu in the middle of the
picture.
Dialog line "End", terminate "with mem.".
With button or enter the correct screen diagonal.
Dialog line "End", terminate "with mem.".
or .
or so that
GRUNDIG Service