Grundig GV 27 Servicehandbuch Seite 16

Service Test Programme & Special Functions
Level 60: Audio Level Adjustment of IC7780 (FV, option)
The audio level is to be adjusted on replacement of the stereo decoder
(IC7780) or the EEPROM (IC7890).
Preparation before calling up this level:
– Connect the AF millivoltmeter to the EURO-AV1 socket, contact 1
– Feed in a white test pattern with sound carrier ("stereo" sound
modulation, right channel 1kHz sine, ±27kHz deviation) to the aerial
input socket
– EE operating mode
On calling up adjustment level 60, the actual setting "0"..."9" is
displayed. Set the output level with the button "–" or "+" to 500mV
±50mV. Each time one of these buttons is pressed the level changes
by 0.5dB and the set value is stored in the EEPROM.
Level 61: Audio Channel Separation of IC7780 (FV, option)
The audio channel separation is to be adjusted on replacement of the
stereo decoder (IC7780) or the EEPROM (IC7890).
Preparation before calling up this level:
– Connect the AF millivoltmeter to the EURO-AV1 socket, contact 3
(left channel)
– Feed in a white test pattern with sound carrier ("stereo" sound
modulation, right channel 1kHz sine, ±27kHz deviation) to the aerial
input socket.
– EE operating mode
On calling up adjustment level 61, the actual setting "0"..."49" is
displayed. Set the noise voltage of the left channel with the button "–
" or "+" to minimum. Each time one of these buttons is pressed the level
changes by 0.1dB and the set value is stored in the EEPROM.
Level 62: Standard Sound Playback Level of IC7850 (AF, option)
The standard sound playback level needs to be adjusted on replace-
ment of IC7850 or of the EEPROM (IC7890).
Preparation before calling up this level:
– Connect the AF millivoltmeter to the EURO-AV1 socket, contact 1
– Feed in a sound signal (1kHz sine, 0.7V
contacts 2 and 6.
– Record the sound signal.
On calling up Level 62, the actual setting "0"..."15" is displayed. Play
back the recorded sound signal (standard sound playback) and set the
output level with the "–" or "+" button to 500mV
one of these buttons is pressed the level changes by 1dB and the set
value is stored in the EEPROM.
Level 99: Timer Clock Output
For adjusting the timer clock (Level 53), the timer oscillator frequency
(approx. 2048Hz) must be measured at this level on IC7201-(80)
"HEST" of the keyboard control unit (DC) (resolution: 6 digits at least).
Note it down (f ).
mess
Note:
After selection of this level, the display is dark and no function of the
VCR is active. This level and the service test programme can be
terminated only by disconnecting the VCR from the mains.
2 - 6
rms
) to EURO-AV1 socket
rms
±50mV. Each time
rms
2. Special Functions
Continuous Operation Test
The continuous recording and playback test is part of the service test
programme and helps to find occasionally appearing faults. The
discovered fault is stored in the EEPROM and is saved even if the VCR
is disconnected from the mains.
Calling up the Continuous Operation Test
– Start the continuous test with button
Terminating the Continuous Operation Test
– Press (STOP) button or
Cleaning the Headwheel
The video heads are cleaned briefly during the period the video tape
is threaded in. By pressing the
mode can be activated for approximately 10s. In doing so, the tape
transport is stopped and the video head cleaning roller is pressed
against the headwheel. Afterwards, play is continued.
Erasing the RAM and EEPROM
Depress the "STANDBY" on the machine while connecting it to the
mains and hold the button for at least 5s.
The EEPROM and the internal processor RAM are erased and
initialized. In doing so, the user programmable station memory and the
timer data are erased. The specific data of the VCR, the tape deck
parameters, VCR option codes, and the adjustment values remain
unchanged.
Replacement of the EEPROM IC7890
Attention: On replacement of the EEPROM, IC7890, the VCR option
codes, Level 40, must be entered and the software must
be readjusted according to the Levels 51, 52, 53, 60, 61
and 62.
Data-Programmer "IDP2"
Note: The transfer of the channel settings stored in the Data-Pro-
grammer is only possible in VCR1 Mode.
– Press "EJECT" button (to eject the loaded cassette).
– Press the (STOP) button on the remote control and
the "INSTALL" button on the video recorder in that order and hold
them down for at least 5 seconds. The display will then show
"MENU".
– Transfer the channel settings with the Data-Programmer "IDP2"
(see Operation Manual "IDP2").
– On completion of the data transfer press
GV 27 ..., GV 47 ..., GV 7...
(Record) or (Play).
"STANDBY" button.
button (min. 5s) the cleaning in play
"STANDBY".
GRUNDIG Service