Adjustment Procedures - Grundig TVR 3735 FR/TOP Service Manual

TVR 3735..., TVR 3740..., TVR 5540...

Adjustment Procedures

GB
Test equipment / aids: Two-channel oscilloscope with 10:1 test probes, voltmeter, colour generator, test cassette, branded video cassette
Service works on replacement of ...
... I703: Adjustment No. 2, 6, 7, 8, 9
... I501: Adjustment No. 2, 6, 7, 8
... I901, I902 or I903: Adjustment No. 4, 6
... the tuner U101: Adjustment No. 2
... the tuner U102 or I201: Adjustment No. 1, 3
... the CRT: Adjustment No. 4, 5, 6, 7, 8
... the tape drum or IN01: Adjustment No. 9
Adjustment
1. Demodulator Voltmeter: ................................................. TP3, I201-(15)
Circuit 2
PAL, L201 Colour generator 38.9MHz, 80dB° V (30mV
tuner U102-(1).
SECAM, Colour generator 33.9MHz, 80dB° V (30mV
R240
tuner U102-(1)
(SUB VCO)
2. Tuner control Allow the TVR to warm up and feed in a standard test
voltage threshold 1 pattern (channel 10, aerial signal level 60dB° V).
Voltmeter: ...................................... plug contact P101-(3)
Activate the Service Mode:
– Press button h and confirm with the G button.
– With the buttons CD select "SPECIAL FUNCTIONS"
and confirm with the G button.
– With the buttons CD select "Service" and confirm with
the G button.
– With the buttons CD select "Service Code" and enter
the code number 8 5 0 0.
– With the buttons CD select "AGC".
3. Tuner control volt- Allow the TVR to warm up and feed in a standard test
age threshold 2, pattern (channel 10, aerial signal level 60dB° V).
R202 Voltmeter: ...................................... plug contact P101-(1)
(SUB AGC)
4. Black level, Allow the TVR to warm up 15 minutes at least on switching
SCREEN (T402) on before making this adjustment.
Feed a black test pattern into the EURO-AV socket.
Activate the Service Mode:
– Press button h and confirm with the G button.
– With the buttons CD select "SPECIAL FUNCTIONS"
and confirm with the G button.
– With the buttons CD select "Service" and confirm with
the G button.
– With the buttons CD select "Service Code" and enter
the code number 8 5 0 0.
– With the buttons CD select "Cut-off" and confirm with
the G button.
Oscilloscope: ............................................. P906-(2, 3, 4)
Determine the highest cathode voltage at P906-(2, 3, 4).
5. Focus, FOCUS Allow the TVR to warm up 15 minutes at least on switching
(T402)
on before making this adjustment.
Feed a grid test pattern into the EURO-AV socket.
6. White balance Allow the TVR to warm up 15 minutes at least on switching
on before making this adjustment.
Feed a grey scale pattern into the EURO-AV socket.
Activate the Service Mode:
– Press button h and confirm with the G button.
– With the buttons CD select "SPECIAL FUNCTIONS"
and confirm with the G button.
– With the buttons CD select "Service" and confirm with
the G button.
– With the buttons CD select "Service Code" and enter
the code number 8 5 0 0.
– With the buttons CD select "WHITE ADJUST" and
confirm with the G button.
GRUNDIG Service
Preparation
) to TP2,
pp
) to TP2,
pp
Adjustment Procedure
With L201 set the voltage to 2.2V.
With R240 set the voltage to 2.2V.
(SUB VCO)
With the F E buttons adjust the voltage so that it is 1V
lower than the maximum voltage (ca. 5V).
Terminate the Service Mode:
– With the buttons CD select "End".
– With the F E buttons select "with mem.", confirm with
the G button and finally press button "TXT".
With R202 adjust the voltage so that it is 1V lower
(SUB AGC)
than the maximum voltage (ca. 5V).
Set the black level at the P906-(X) with the highest
≤
cathode voltage to 130V 5V using the adjustment control
SCREEN at the line transformer (T402).
Terminate the Service Mode: Press the "TXT" button.
Adjust the focus control (FOCUS) at the line transformer
(T402) to obtain the sharpest grid lines.
With the buttons CD select "Green" or "Blue".
With the F E buttons adjust the "Green" and "Blue" colour
so that no discolouration is visible in the grey scale.
Terminate the Service Mode:
– Press button h.
– With the buttons CD select "End".
– With the F E buttons select "with mem.", confirm with
the G button and finally press button "TXT".
Adjustment Procedures
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