GRUNDIG GV 5000GB
Manual de Servicio

Abgleich / Adjustment Procedures

GV 5000 �, GV 5300 �

2.2 Family Board � Frontend (FV)
Test equipment: Oscilloscope with 10:1 Test Probe, Voltmeter, Colour Generator Service work after replacing the Tuner: Adjustments no. 2 Adjustment 1. Vision Demodulator Circuit, F5770 2. Delayed AGC Voltage, R3770 Preparation Feed in 38.9MHz / 100mVPP into the tuner output 1701-(17). Voltmeter: ..................................................... IC7772-(10) EE-mode. Feed in a PAL white test pattern with sound carrier (without sound modulation, UHF-range, Ch24, 67dBµV aerial signal) into the warmed-up VCR. Oscilloscope: ......................................... Tuner 1701-(17) EE-mode. Adjustment Procedure Set the voltage with F5770 (AFC) to 2.5V ±0.2V.

Set the amplitude with R3770 (AGC) to 550mVPP +0/-50mV.

2.3 Family Board � Video/Chroma (VS)
Test equipment: Oscilloscope with 10:1 Test Probe, Frequency Counter, Colour Generator Service work after replacing the Family Board: � Adjustment 1. Frequency Deviation Sync Value, R3054 2. Chroma Writing Current, R3038 Preparation AV recording (do not feed in an signal). Frequency counter: ............................................ 1911-(2) Connect IC7051-(2) to +5V. Oscilloscope: ...................................................... 1911-(2) Feed in a PAL red raster test pattern with 75% saturation (ratio burst: chroma = 1 : 2.2). AV recording. Adjustment Procedure Set frequency counter with R3054 (Sync. Frequ.) to 3.8MHz

±10kHz.
Set Chroma signal with R3038 (CHROMINANCE WRITING CURRENT PAL) to 71mVPP (-12.5dB of the FM-signal). Disconnect IC7051-(2) from +5V.

2.4 Family Board � Standard Sound / Audio Linear (AL)
Test equipment / aids: AF Millivoltmeter, AF Generator, Video Cassette of reputable brand. Service work after replacing the Family Board or the RP-Head: Adjustment no. 1.1, 2 Adjustment 1. Erase Frequency 70kHz, F5603 1.1 Bias (70kHz), R3618 1.2 Frequency Response Test Preparation Frequency counter: ............................................. 1918-(7) Record AF millivoltmeter: ................................................... R3600 Record. � Connect IC7601-(10) via 270� resistor to ground. � Feed in a CCVS signal via EURO-AV socket, contact 20. � Feed an audio signal of 200mVrms (480mVPP) from the AF generator to the EURO-AV socket, contact 2 or 6. � Make a recording of 400Hz and 8kHz each of 1 min at least. Afterwards play back these recordings. � Connect an AF millivoltmeter (oscilloscope) to EURO-AV socket, contact 1 or 3. AF generator (1kHz / 0.7Vrms): ..................................... EURO-AV socket, contact 2 or 6 AF millivoltmeter: ......... EURO-AV socket, contact 1 or 3 Record (Normal Play). Play back this recording. Adjustment Procedure With F5603 (BIAS Frequ.) set the reading on the frequency counter to 70kHz ±10kHz. Set the voltage drop across R3600 with R3618 15mVrms. Check the frequency response.
(BIAS)

to

The voltage ratio of 400Hz to 8kHz must not be higher than 1:0.7 or 0.7:1 (±3dB). If the voltage ratio exceeds these limits, the bias must be altered: To increase the playback voltage at 8kHz: Reduce "BIAS". To reduce the playback voltage at 8kHz: Increase "BIAS". Remove the 270� resistor between IC7601-(10) and ground. Set output voltage with R3606 (PB-Lev.) to 0.5Vrms ±50mV.

2. Playback Level, R3606

3. Keyboard Control Unit (ODCG1)
Test equipment: Frequency Counter Service work after replacing the Keyboard Control Unit: �

Adjustment 1. Clock, C2005

Preparation Disconnect from the mains. IC7101: ....... Connect Pins 67 and 68 with Pin 33 (+5V). Frequency Counter: ............................................ 1101-(1) Reconnect to the mains.

Adjustment Procedure The period is set with C2005 (CLOCK ADJ.) to 488.281,25ns ±0,715ns by the manufacturer. Disconnect IC7101-(67), -(68) from +5V (Pin 33).

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