Grundig GT 2105, GT 2005 Service Manual

SERVICE MANUAL

Service Manual

Sach-Nr./Part No.

72010-019.10

TRC 1 (75990-200.14) TRC 2 (75990-300.00)

Additionally required Service Manuals for the Complete Service:

Service Manual

Sicherheit

Safety

Sach-Nr./Part No.

72010-800.00

Btx * 32700

Chassis G 1000 Stereo (ST 03)

GT 2005 (77250-056.61/GCC 1261GB) GT 2105 (77250-055.61/GCC 1361GB)

Attention: The picture tube panel must be removed

before disconnecting the yoke plug

Änderungen vorbehalten Printed in Germany Service Manual Sach-Nr. Subject to alteration VK 221 0596 Service Manual Part No. 72010-019.10

General Section ST 03

The regulations and safety instructions shall be valid as provided by the "Safety" Service Manual, part number 72010-800.00, as well as the respective national deviations.

Safety Advice

The X-radiation developing in the sets conforms to the X-radiation Regulations (January 8, 1987), issued by the Physikalisch-Technische Bundesanstalt (federal physiotechnical institution). The high tension for the picture tube and thus the developing Xradiation depends on the precise adjustment of the +A power supply. After every repair of the power supply unit or the horizontal deflection stage it is imperative that the EHT for the picture tube is checked and re-adjusted if necessary. To avoid consequential damages to the chassis or the picture tube the integrated protective circuits are allowed to be put out of operation only for a short time. When replacing the picture tube use only the types specified in the spare parts lists.

Table of Contents

Page

General Section .....................................1-1... 1-8

Safety Advice ............................................................................... 1-2

Technical Data..............................................................................1-2

Remote Control TRC 1 .................................................................1-3

Remote Control TRC 2 .................................................................1-3

Brief Service Instuctions ...............................................................1-4

Fasttext Operation ........................................................................1-4

Operating Hints.............................................................................1-5

General Part

Test Equipment / Aids

Variable isolating transformer Test/Sweep Generator Colour Generator Oscilloscope DC Voltmeter AF Voltmeter AF Generator Frequency counter

Please note the Grundig Catalog "Test and Measuring Equipment" obtainable from:

Grundig electronics GmbH Würzburger Str. 150 D-90766 Fürth/Bay. Tel.0911/703-0 Telefax 0911/703-4479

Technical Data

TV Receivers .............................................. 20" / 21"

Mains voltage.............................................. 220…240V ~ 50/60Hz

Control range of the power supply ..............190…264V

Circuit Descriptions..............................2-1... 2-3

1. Power Supply .........................................................................2-1

2. Tuner and Demodulator Circuits ............................................2-1

3. Peritel Output .........................................................................2-1

4. Video Chroma Processing ..................................................... 2-1

5. Delay Line ..............................................................................2-1

6. Time Base Generator .............................................................2-2

7. RGB Drivers ...........................................................................2-2

8. System Microcontroller (IC500).............................................. 2-2

9. Output Power Stages .............................................................2-3

10. Video Output Stages ..............................................................2-3

11. Teletext Options......................................................................2-3

12. Power Supply to MSP 3400/3410 .......................................... 2-3

13. Second Peritel and Mute Circuit.............................................2-3

14. Audio Amplifier........................................................................2-3

Alignment ....................................................... 3-1

Layout of the PCBs

and Circuit Diagrams.........................4-1... 4-22

Chassis Board ..............................................................................4-1

Oscillograms ................................................................................ 4-8

Deflection H+V............................................................................4-10

Power Supply............................................................................. 4-11

Signal Board .............................................................................. 4-13

Y/C Processing ...........................................................................4-15

Audio Board Circuit Diagram ......................................................4-17

Audio Board PCB........................................................................4-19

Text ............................................................................................ 4-21

CRT Panel ................................................................................. 4-21

Screen diagonal.......................................... 51cm / 55cm

Picture diagonal .......................................... 48cm / 52cm

Power consumption .....................................ca. 55W

Power consumption in Standby ...................ca. 8W

Aerial socket ............................................... 75 Ω coaxial plug

Programmes ............................................... 99 + 2AV

Standard ..................................................... PAL/I

Output power .............................................. 2x5W RMS

Temperature range ......................................0 - 40° C

Spare Parts List .................................... 5-1... 5-4

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ST 03 General Section

Remote Control TRC 1

123

456

789

0/AV

P+

P-

TEXT/MIX

HOLD

TRC 1

TUNE

EXP

VOL+

VOL-

STORE

Remote Control TRC 2

123

S R Q

O N

456

789

0/AV

TUNE

AUDIO

LANG 1/2 STEREO

INDEX

TRC 2

STORE

VOL+

VOL-

P+

P-

TEXT/MIXHOLD EXP

D E

Operation of the Remote Control Keys

8 Switches the receiver on and off (Standby)

1-0 Direct channel selection and direct entry of adjustable

settings. Turns television on from Standby.

P+ Selects channel above current channel. Increases

adjustable menu settings.

P- Selects channel below current channel. Decreases

adjustable menu settings.

VOL+ Increases Volume VOL- Decreases Volume

i Displays selected channel number. Accesses hidden

information. MENU Accesses Menu STORE Stores channels in tuning mode TUNE Selects tuning mode

e Mutes sound

HOLD Holds a particular page in the Teletext mode EXP Changes height of characters in the Teletext mode TEXT/MIX Selects teletext/selects mixed mode (text on picture) TV Returns to normal viewing mode 0/AV Selects auxiliary mode

Operation of the Remote Control Keys

A Direct channel selection or page number in teletext mode. Switches

the television on from standby. B Switches set to standby or switches set on from standby C Increases and decreases the volume D Displays the selected channel E Stores channels in tuning mode F Increases or decreases adjustable settings G Returns to normal viewing mode H Mutes sound I Selects teletext/selects mixed mode (text on picture) J Changes height of characters in teletext mode K Fasttext buttons L Holds a selected page in teletext mode M Selects index pages in teletext mode N Selects between stereo, stereo-wide and pseudo-stereo O Selects language in dual language Nicam transmissions.

Selects mono sounds. P Accesses menu Q Accesses audio selections R Selects tuning mode S Selects auxiliary input

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General Section ST 03

Brief Service Instructions

Tuning

Press the "Tune" key on the remote control to bring up the tuning graphic "S". Press and hold the "P+" key for more than 1 second to start the search tuning. When a channel is found the "S" graphic will flash. Either select "P+" to continue tuning or "Store" to retain the channel. By pressing the "Store" key the programme number will flash, key in the programme number that the channel is to be store in. To exit the tuning screen press TV.

Fine Tuning

Press the "Tune" button and then the "HOLD" key briefly to bring up the fine tuning graphic. An X will appear after the channel number. Use the "P+" and "P-" keys to fine tune and then "Store".

Scart Menu

Press the "0/AV" button and then the "Tune" key the Scart options graphic will appear, with VCR, DECoder and AUX. In the VCR mode only, the line time base time constant is short. In Decoder mode Pin 8 of the Scart is enabled whilst tuning to allow for tuning of decoded channels.

Fasttext Operation

In addition to the standard Teletext functions, the receiver GT 2105 has Fasttext. This system provides more value from Teletext by allowing fast access to highlighted pages and by linking many related pages for easy access.

The key to Fasttext is four colour coded prompts at the bottom of each teletext page. These red, green, yellow and blue prompts relate to the four colour coded buttons on the tv remote control.

Each colour coded prompt acts as a "signpost" through the huge choice of Teletext pages available, allowing faster and easier access to highlighted pages.

Use of Fasttext

To select any colour coded page from Teletext press the corresponding coloured button on the TV remote control.

The new page selected will appear almost instantly although there can still be a delay for some pages to appear. This is particularly the case if a rapid succession of coloured Fasttext buttons are pressed.

As new pages are accessed, at the bottom of the page a new series of subject related colour coded prompts will appear.

Fasttext Index Function

To return any time to the main index pages it is not necessary to enter the index page number.

INDEX To return to the main index press the INDEX button once. INDEX With the main index on screen a further press of the INDEX

button will access the main A - Z index or other subsidiary index pages.

Returning to Normal Television Viewing

TV To return to normal television viewing at any time, press the

TV button.

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GRUNDIG Service 1 - 5

Operating Hints GT 2005 / 2105

Note: This chapter contains excerpts from the operating instructions. For further particulars please refer to the appropriate user instructions the part number of which is indicated in the relevant spare parts list.

ST 03 General Section

TUNING IN

TUNING

Your TV set can memorise 99 different channels. During channel tuning any connected satellite receiver or video recorder should be switched to standby. To tune in different channels, follow the instructions below.

Step 1 Press TUNE on the remote control.

A tuning bar will appear. Step 2

Press P+ for approximately one second. The set will scan up through the available channel

frequencies. A cursor moves slowly up the bar until

'S'

a channel is found. The S will now flash on and off. If you do not wish to store the channel, press P+

again until a required channel is found. Step 3

Press STORE to memorise the channel. The programme setting PO1 will now flash on and off.

Step 4 Decide which channel number you want to allocate the channel to e.g. BBC1 = 1. Press the appropriate number e.g. 1.

FINE TUNING

After following the TUNING instructions you should have a clear picture on all channels (subject obviously to the reception quality of the incoming signal). If any channels are not to the standard you would expect, fine tuning may sometimes improve the picture quality. To fine tune follow the steps below:

Step 1 Select the channel to be tuned. If the tuning bar is no longer on screen press TUNE. If it is, move onto step 2.

Step 2 Press HOLD very briefly. An X will appear besides the programme number to indicate that fine tuning has been selected.

Step 3 By briefly pressing P+ or P-, fine tune the picture.

Step 4 When the best possible picture has been achieved, press STORE twice to memorise the settings.

Step 5 To return to normal television viewing press TV.

Note : the X symbol means that the Automatic Frequency Control (AFC) has been switched off. Channels stored with the X displayed may drift off tune and therefore fine tuning should only be used if absolutely necessary.

Step 5 Store the setting by pressing STORE.

The channel is now stored against the chosen channel number. The tuning bar will still be on screen and the S will still flash.

Now tune the remaining channels. Repeat steps 2, 3, 4 and 5 until all channels are tuned in.

To exit the tuning screen press TV.

TUNING INTO A VIDEO RECORDER, SATELLITE RECEIVER OR GAMES CONSOLE

If connecting a video recorder, satellite receiver or games console to the television set via the scart sockets (see page 3 and 14), press 0/AV on the remote control. Alternate presses of 0/AV selects between the AV inputs, AV1 and AV2.

If making the connection via the television sets aerial,

select channel 99 as the dedicated channel by pressing 9 twice.

1 - 6 GRUNDIG Service

General Section ST 03

With the video recorder, satellite receiver or games console on, tune channel 99 to the output following steps 1-5 in the TUNING IN SECTION on pages 4 to 5.

When using the 0/AV mode the on screen display can be adjusted to indicate whether a video recorder, external decoder or auxiliary source (e.g. a games console or satellite receiver) is connected. Follow the steps below selecting first either AV1 or AV2 input as required.

Step 1 Press 0/AV on the remote control.

Step 2 Press TUNE on the remote control. The display will show 3 options;

(vcr)

DEC (decoder) AUX (satellite receiver or games console).

Step 3 Further pressing of TUNE allows the desired symbol TUNE to be highlighted in yellow. When the required symbol is highlighted the setting will automatically store after five seconds.

STANDBY AND CHANNEL CONFIRMATION

STANDBY MODE

When the television is in standby it can be switched on by pressing either P+ or P- or by pressing the channel number required, e.g. 1 for BBC 1. Alternatively press

STANDBY.

CONFIRMATION OF CHANNEL SELECTED

Whenever a new channel is selected the top left hand corner of the screen will confirm the channel number selected for approximately 5 seconds.

To confirm or check the channel being watched without changing channel, press i. The channel number selected will be displayed in the top left hand corner of the screen for approximately 5 seconds.

Note : Pressing i will confirm the channel details at the bottom of the screen.

PICTURE ADJUSTMENT

Your Grundig television set allows control of brightness, contrast and colour. To make any picture adjustments follow this procedure :

BRIGHTNESS CONTRAST AND COLOUR

Step 1 Press MENU.

The brightness symbol will be displayed with a cursor which indicates the current brightness setting.

Step 2 With the cursor on screen adjust the brightness by using P+ or P-. The cursor moves to indicate the change. The new setting is automatically stored.

Step 3 To change the other settings, with the brightness control on screen, press MENU. The brightness symbol before the cursor will change to the contrast setting.

Step 4 Adjust the contrast by using P+ or P-.

Step 5 With the contrast setting on screen press MENU again.

The contrast symbol before the cursor will change to the colour setting.

Step 6 Adjust the colour setting to your liking by using P+ and P-.

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ST 03 General Section

The cursor will move to indicate the change. To return to normal viewing press TV.

AUDIO ADJUSTMENT

VOLUME CHANGE AND MUTE

To increase the volume press VOL+. To decrease the volume press VOL-.

To mute the sound, press .

To restore the sound when muted press again.

BASS, TREBLE AND BALANCE ADJUSTMENT

To make the most of high quality NICAM stereo transmissions you can alter the bass, treble and balance to your preference. Follow these steps:

Step 1 Press AUDIO until the audio selection screen is displayed. The bass symbol will be displayed with a cursor which indicates the current bass level selected.

Step 2 With the cursor on screen adjust the bass level using P+ or P-. The cursor moves to indicate the change.

Step 3 To change the treble level with the audio selection screen displayed press AUDIO until the treble symbol is displayed.

Step 4 With the cursor on screen adjust the treble level using P+ or P-.

Step 5 To change the balance with the audio selection screen displayed press AUDIO until the balance symbol is displayed.

Step 6 With cursor on screen alter the balance in favour of the left or right TV speaker with P+ or P-.

Note: If no further buttons are pressed the audio selection screen will disappear within 5 seconds and any changes made will be stored.

STEREO WIDE SELECTION

Your Grundig NICAM stereo television allows you to enhance the stereo effect from stereo transmissions by selecting Stereo Wide. To select Stereo Wide follow these steps:

Step 1 Press STEREO. Either (stereo) or

(stereo wide) symbols will appear. Step 2

Repeated presses of STEREO will alternate between stereo and stereo wide allowing the selection of whichever is preferred. Once the required stereo selection is made the on screen symbol will disappear after 5 seconds and the selection will be stored.

PSEUDO STEREO SELECTION

If the transmission is not in stereo no symbol will be displayed. It is possible to give the mono sound a stereo like sound by following the steps in stereo wide selection above.

Either (mono) or (pseudo stereo) can be selected.

MONO SOUND SELECTION

On the edge of a NICAM stereo transmission area the stereo sound may be intermittent, resulting in poor sound quality, popping and clicking noises. If this is the case the programme can be listened to in mono instead of stereo, by pressing LANG 1/2. The symbol will indicate that mono sound has been selected. A second press will restore the stereo symbol and stereo sound.

9 10

1 - 8 GRUNDIG Service

General Section ST 03

MULTI LANGUAGE OPERATION

In the future some television programmes may be transmitted with a choice of language selections. Your Grundig television is ready for this development. If programmes are transmitted in this way, pressing LANG 1/2 will alternatively select between the dual language audio soundtracks which will be in mono.

SETTING THE SLEEP TIMER

Should you fall asleep whilst watching television, or leave the television set on unattended, your Grundig Television set will automatically switch into standby 10 minutes after the end of transmissions.

You can however, programme the television to switch into standby between 1 minute and 90 minutes ahead.

This ensures that should you fall asleep before the end of a programme, the television set will automatically switch off, instead of remaining on until the end of the last programme of the day. To activate the sleep timer follow these steps:

Step 1 Press MENU until the timer off symbol is displayed.

Step 2 Press either P+ or P-. The timer on symbol will be displayed along with the time in minutes until the

automatic switch off will be activated.

ADDITIONAL INFORMATION

CARE OF YOUR SET

Use only a soft cloth to clean your television set cabinet. Normal window cleaning products can be used to clean the screen.

Never use strong detergents, abrasive cleaner or polish to clean either the cabinet or the screen.

SCART USAGE

If only one SCART connector is to be used it is advisable to use SCART 1. If both are to be used the following use of Scart connections is likely to be most suitable:

Products Scart 1 Scart 2

VCR and Satellite Receiver VCR Satellite Receiver

VCR and Games Console Game VCR

VCR and Hi-Fi Hi-Fi VCR

Satellite Receiver and Hi-Fi Hi-Fi Satellite Receiver

Step 3 Press P+ or P- to set the time in minutes until the television set will switch off.

Pressing P+ will increase the minutes from 1-90. Pressing P- will decrease the minutes from 90-1. When the correct advanced switch off time is selected,

if no further buttons are pressed the set will revert to

normal viewing and automatically switch off after the pre-determined time. To ensure that the timer will not activate alter the switch off time to zero.

+ 18 hidden pages