GRUNDIG CUC 7880, CUC 7890 Service Manual

1GRUNDIG CUC 7880

Matrix

Item See Model Book

Service Notes (See Notes) ......................................................... Grundig G1000 Chassis 4

X-Ray Precautions(See Notes)............................................. Grundig G1000 Chassis 4

AF Amp PCB ........................................................................................ Grundig CUC 7851 5

CRT PCB............................................................................................... Grundig CUC 7861 5

IF Amp PCB .......................................................................................... Grundig CUC 7861 5

IF Amp PCB (alternative) .................................................................... Grundig CUC 7851 5

Remote Control ................................................................................... Grundig CUC 6360 5

Socket PCB .......................................................................................... Grundig CUC 7861 5

Tuner Diagram ..................................................................................... Grundig CUC 5301 3

Recommended Safety Parts

Item Part No. Description

ST82 775

C 6001 8511-793-047 MP 3 0,47 UF 20% 250VW C 6002 8511-793-033 MP 3 0,22 UF 20% 250VW L 6001 29500-809.97 FUNKENTSTOERDR R 6009 8311-200-010 DUO-PTC R 816, R 817 8766-701-027 KSW SI A 12 OHM 5% -GA SI 6001 8315-622-003 FS.3,15 A/T L 250V WW. 09246-196.71 Degaussing Coil WW. = Optional

ST 8277

CUC 7880

C 621 8660-098-238 SI-KERKO B-SS 2200PF 20% 400V C 622 8660-098-238 SI-KERKO B-SS 2200PF 20% C 665 8660-098-234 SI-KERKO B-SS 1000PF 20% 400V C 666 8515-912-063 FKP1 0,033UF 20% 630V R 503 8701-230-817 NKS 3 4,7 OHM 5% >>>RES R 520 8705-329-071 MOW LI 0411 820 OHM 5% R 525 8735-003-068 DW 0,75W 0,68 OHM 10% R 552 8700-229-009 KSW AX 0207-GA NB 2,2 OHM R 665 8718-250-155 Z 0414 2,7 MOHM VDE CECC R 667 8735-002-013 DRW 2 W 0,1 OHM 10% SI 401, 406, 411 8315-616-205 LOET-SI.-GR 800 MA/T SI 630 8315-619-028 LOET-SI.-GR 1,6 A/T SI 671 8315-622-025 LOET-SI.-GR 3,15 A/T SI 691 8315-623-008 LOET-SI.-GR 4 A/T TR 410 29201-380.97 UEBERTRAGER TR 526 29201-029.08 DIODENSPLITTRAFO KPL TR 651 29201-369.97 SPERRWANDLERTRAFO KPL WW. 29201-453.46 SPERRWANDLERTRAFO KPL WW. = Optional

ST82 775/9

09246-196.31 Degaussing Coil 8300-020-758 Pict. Tube A 76 JTS 90X08 29201-377.02 CRT Cable 09621-113.02 Fuse Holder 29303-452.02 Mains Plug - Lower Part 29703-291.32 Power Switch 8290-991-307 Mains Cable 09032-301.01 Power Transformer

09246-196.31 Degaussing Coil 8300-020-758 Pict. Tube A 76 JTS 90X08 29201-377.02 CRT Socket 09621-113.02 Fuse Holder 29303-452.02 Mains Plug - Lower Part 29703-291.32 Power Switch 8290-991-307 Mains Cable 09032-301.01 Power Transformer 29305-165.06 Power Switch Board

29305-025.32 Focusing Control Unit 29201-361.13 Focus and UG 2 Control

09246-196.31 Degaussing Coil 8300-020-758 Pict. Tube A 76 JTS 90X08 29703-291.32 Mains Switch 09621-113.02 Fuse Holder 29303-452.02 Mains Plug - Lower Part 09032-301.01 Power Transformer 29305-165.06 Power Switch Board

Recommended Safety Parts

Item Part No. Description

CUC 7880

SI 401, 406, 411 8315-616-205 LOET-SI.-GR 800 MA/T SI 630 8315-619-028 LOET-SI.-GR 1,6 A/T SI 671 8315-622-025 LOET-SI.-GR 3,15 A/T SI 691 8315-623-008 LOET-SI.-GR 4 A/T TR 410 29201-380.97 UEBERTRAGER TR 526 29201-029.08 DIODENSPLITTRAFO KPL TR 651 29201-369.97 SPERRWANDLERTRAFO KPL WW. 29201-453.46 SPERRWANDLERTRAFO KPL WW. = Optional

ST82 775/9 PIP

CUC 7880

C 621, C 622 8660-098-238 SI-KERKO B-SS 2200PF 20% 400V C 665 8660-098-234 SI-KERKO B-SS 1000PF 20% 400V C 666 8515-912-063 FKP1 0,033UF 20% 630V OK 637, 646 8306-000-012 OPTOKOPPLER CNY 17 F1 R 503 8701-230-817 NKS 3 4,7 OHM 5% >>>RES R 520 8705-329-071 MOW LI 0411 820 OHM 5% R 525, R 552 8735-003-033 DW 0,75W 0,33 OHM 10% R 665 8718-250-155 Z 0414 2,7 MOHM VDE CECC R 667 8735-002-013 DRW 2 W 0,1 OHM 10% SI 401, 406, 411 8315-616-205 LOET-SI.-GR 800 MA/T SI 630 8315-619-028 LOET-SI.-GR 1,6 A/T SI 671 8315-622-025 LOET-SI.-GR 3,15 A/T SI 691 8315-623-008 LOET-SI.-GR 4 A/T TR 410 29201-380.97 UEBERTRAGER TR 526 29201-029.08 DIODENSPLITTRAFO KPL TR 651 29201-369.97 SPERRWANDLERTRAFO KPL WW. 29201-453.46 SPERRWANDLERTRAFO KPL WW. = Optional

ST95 775/9 PIP

CUC 7890

C 665 8660-098-234 SI-KERKO B-SS 1000PF 20% 400V C 666 8515-912-063 FKP1 0,033UF 20% 630V C 7 8531-505-221 MKT 1816 ROE/B32237 SIE/ OK 637, 646 8306-000-012 OPTOKOPPLER CNY 17 F1 R 503 8701-230-817 NKS 3 4,7 OHM 5% >>>RES R 520 8705-329-071 MOW LI 0411 820 OHM 5% R 525 8735-003-033 DW 0,75W 0,33 OHM 10% R 552 8700-229-009 KSW AX 0207-GA NB R 665 8766-349-155 MSW LI 0414 2,7 MOHM R 667 8735-002-013 DRW 2 W 0,1 OHM 10% SI 401, 406, 411 8315-616-205 LOET-SI.-GR 800 MA/T SI 630 8315-619-028 LOET-SI.-GR 1,6 A/T SI 671 8315-622-025 LOET-SI.-GR 3,15 A/T SI 691 8315-623-008 LOET-SI.-GR 4 A/T TR 410 29201-380.97 UEBERTRAGER TR 526 29201-029.08 DIODENSPLITTRAFO KPL TR 651 29201-369.97 SPERRWANDLER KPL TR 8 29201-445.97 FOKUSIERUEBERTRAGER WW. 29201-453.46 SPERRWANDLERTRAFO KPL WW. = Optional

29201-361.13 Focus and UG 2 Control

09246-196.31 Degaussing Coil 8300-020-758 Pict. Tube A 76 JTS 90X08 09621-113.02 Fuse Holder 29303-452.02 Mains Plug - Lower Part 09032-301.01 Power Transformer 29305-165.06 Power Switch Board

29201-361.13 Focus and UG 2 Control

09246-199.71 Degaussing Coil 8300-020-893 Pict. Tube A 89 JTS 96X01 09621-113.02 Fuse Holder 29303-452.02 Mains Plug - Lower Part 09032-301.01 Power Transformer 29305-165.06 Power Switch Board 29501-532.01 Cover 29703-291.32 Power Switch

29201-361.13 Focus and UG 2 Control

Service Adjustments

Options for Servicing With the remote control buttons

EPROM Version Number

The version number, week and month of production, can be called up in the Info Menu with the “AUX” button. The index 02 of the part number (19798-254.02) indicates the EPROM version.

Changing the Display Brightness

The VFD brightness is changed by pressing the “AUX” --> buttons sequentially.

Programme Lock (protection against unauthorised use)

This electronic combination lock can be cancelled by pressing , and and OK

sequentially.

One Place/Two Place Programme Selection

The options 1 - 9 or 1 - 99 can be selected via the menu Info Centre --> Special Functions ->Settings --> Programme Selection.

Maximum Programme Number

When storing the channel number “00” at any programme position, programme selection with

buttons is limited to the numbers lower

than this position.

OSD-ON/OSD-OFF - all programmes.

The on screen display can be switched on or off via the Menu Info Centre --> Special Functions -

-> Settings --> Pict./Sound Options. When selecting the OSD-OFF option the station identifications and scales for the analog values is switched off.

OSD-ON/OSD-OFF - individual programmes

Activate the desired station via the menu Info Centre --> TV Station Table and enter a decimal point “.” at the first place of the station identification. With this setting the display can be switched off for the selected programmes.

Changing the Sharpness

Call up the Info Menu --> Sharpness and change the value with .

Hi-Fi Output: off, variable, linear Via the Audio Menu --> Hi-Fi Output, with the buttons ,

the AF at the Hi-Fi output can be:

- Switched “off” (display shows P..), normal operation.

- Set to “variable” (display shows H..), volume level adjustment for the Hi-Fi system can be changed via the TV remote control. The loud speakers in the TV receiver are switched off in this case.

- Set to “linear” (display shows H..), constant level for the Hi-Fi system.

Switching Over the Sound: Stereo, Mono, FM, NICAM, NICAM B

Via the Audio Menu --> Sound it is possible with the buttons to change over the stereo

decoder for the desired sound reception.

Forced Mono

By entering the station identification “MONO” or “.ONO” the stereo decoder can be made to switch over to FM-mono. If a decimal point is entered in the first place of the station identification this indication does not appear on the screen.

Volume Level Matching

Via the Menu Info Centre --> Settings -->

Volume it is possible on RF mode and Peri mode to set a volume offset on each TV programme position (volume level matching).

Switching over the descrambler: (AV1 socket black)

“AUX” --> “0/AV”. With the “0/AV” button select: Descrambler off Descrambler on Auto Descrambler on Stereo Descrambler on Mono - L Descrambler on Mono - R The switching voltage present at the EURO-AVsocket changes automatically to Descrambler operation.

Setting the Peri Bit

“AUX” --> “ “0/AV”. With the Peri bit set, the control processor evaluates the switching voltage on pin 8 of the EURO-AV-socket AV1 and switches the TV receiver to this input, eg. on descrambler operation.

Monitoring the AV Connection

Video source on the AV1 socket, via IDTV Menu

--> AV Monitor.

Copy Function

In operating mode: Select first the AV signal source eg. AV1, AV2 etc.

- On: “AUX” --> “0/AV” indication “Copy on”

- Off: “AUX” --> “0/AV” indication “Copy off”

Copying possibilities:

From To: Scart socket, black: AV1 --> scart socket 2 (orange).

--> scart socket 3 (blue). Scart socket, orange: AV2 --> scart socket 3 (blue). Scart socket, blue: AV3 --> scart socket 2 (orange). Cinch socket: AV4 --> scart socket 2 CCVS --> scart socket 3 S-Video socket: AV5 --> scart socket 2 (orange).

--> scart socket 3 (blue).

In stand-by mode:

Select first the AV signal source eg. AV1, AV2 etc.

- On: “AUX” Æ “0/AV”. Indication “Copy on”.

- Buttons “AUX” Æ “ ”. (Standby) Indication “C”

or “COPY” dependant on the display. Copying possibilities are the same as before.

- To cancel the copy mode press “ ”or “mains

off”.

IR-Data Programmer

With this menu and with the IR-Data Programmer 2 it is possible to store a maximum of 99 programme positions with the data for the TV norm, Peri, 6-place station identification and the fine tuning frequency. The programmer AP transfers only channels and 4-place station identifications.

-Call up via the Menu Info Centre --> Special Functions --> IR-Data Programmer.

Emergency Data

If necessary the emergency data can be read out from the EPROM. See “Service Adjustments”.

Service Adjustments Colour Registration

The colour registration function allows to compensate for differences in the delay between the Y-channel and the chroma channel.

- with the Menu guide call up the “Colour

Match” menu via the Service Programme, Info Centre --> Special Functions --> Service -

-> Code 8500.

- with buttons correct the delay so that the

Y chroma signals coincide.

2GRUNDIG CUC 7880

Sevice Adjustments Cont’d.

Tuner AGC

The automatic Gain Control offers two possibilities of adjusting the delayed automatic gain control voltage for the tuner: 1: Feed a standard test pattern at a channel in

the upper range of the UHF band into the aerial socket. The RF should be 1.5mV (64dBmV). Call up the “Tuner-AGC” menu via the Service Programme Info Centre --> Special Functions --> Service --> Code 8500, select “automatic” and confirm. The control processor will set the correct value for the delayed gain control voltage.

2: Feed in a standard test pattern at a UHF

channel as high as possible to the aerial socket. Call up the “Tuner-AGC” menu via the Service Programme Info Centre --> Special Functions --> Service --> Code 8500, select

“manual” and confirm.With the buttons tune the TV station so that noise just begins to appear in the picture. Then tune in the reverse direction until the picture just becomes noise free. Store with “OK”.

Tuner AFC

On RF video recorder reproduction the Automatic Frequency Control is activated is activated only if the desired programme position is marked with the station identification AV.

- Tune the tuner precisely at a programme position.

- Call up the AFC Reference Menu via Service Programme Info Centre --> Special Functions --> Service --> Code 8500 --> with the menu guide and activate with “OK”.

On activation of the AFC function a voltage level is read out from the IF-amplifier which is used as a reference for AV-programmes.

Loading the Average Values

Press and hold the P- button on the local keyboard and switch the TV on with the mains button. In doing so, the analog average values for the programmes 1-99 and AV1- AV5 are stored in the programme memory IC840, the AV and switch-on bits are reset, and the ATS bit is set. The individual settings can be entered and stored with the remote control handset.

ATS Reset

Press and hold the L+ button on the local keyboard while switching on with the mains button. With this option the programmes 1 - 99 are pre-programmed with the analog data for brightness, colour contrast and volume level. Additionally, the bits AV, France are reset and the ATS bit is set.

Load Emergency Data (ex. after changing mP IC850)

Connect pin 2 of the processor to chassis and switch on the TV by power switch. The EEPROM in the processor IC850 is loaded with:

- the data set and the geometry data for

the IC TDA 9160

- the white balance data VR, VG and VB

for the IC TDA 9160

- the IF and AFC control voltages

- The PI data set

- the data sets for the programmes 47 - 99.

White Balance

- Call up the White Balance menu via the

Info Centre --> Special Functions --> Service --> code 8500.

- with the buttons set the VG

(amplification green) and VB (amplification blue) values so that the

white rectangular area in the middle of the picture becomes achromatic. Store with OK.

Adjustment of the Screen Grid voltage U

- Feed in a test pattern

- With the remote control adjust the screen brightness so that the grey areas just become dark.

- Switch the receiver to AV operation.

- Connect a high-ohmic voltmeter (series resistance 220k Ohm approx.) to the test points R,G,B and determine the highest voltage.

- With the control U set the highest voltage level to approx. 175V.

- If retrace lines are visible on the screen reduce the voltage by approx. 10V.

Adjustment of the Bridge Coil L511

- Call up the Geometry Menu via the

Service Programme --> Info Centre --> Special Functions --> Service --> Code

8500. Set the horizontal amplitude to minimum.

- Connect one test probe of a dual-beam

oscilloscope to the collector of the transistor T572.

- Connect the second test probe

between the diodes D502 and D503.

- Adjust the coil L511 so that the pulse

width of both oscillogrames is the same.

- Re-adjust the horizontal amplitude

according to the test pattern and store.

Adjustment of the Line Sharpness

With the focus control on the adjustment control panel adjust the lines in the north-south direction for maximum sharpness. TV receivers with focusing panel:

Subsequently, with the focus control on the focusing panel, adjust the lines in the east-west direction for maximum sharpness. Repeat if necessary.

Attention: For measurements on the focussing panel use only sufficiently insulated measuring cables and test probes with adequate electric strength (eg. 100:1).

Videotext (VT) Matching Adjustment

At the time of delivery the control R378 is set to the lowest high-frequency emphasis. If, despite a perfect aerial signal, character faults occur, turn R378 slowly until the character errors disappear. Do not turn R378 any more as the error rate may increase again. During this adjustment page 199 must always be selected anew so that it is read in anew making it possible to evaluate the error rate.

Setting the Micro picture (PIP)

For setting the micropicture press and hold the PIP button on the remote control handset and switch on with the mains button.

Possible settings with the remote control buttons:

- Vertical movement of the PIP:

- Horizontal movement of the PIP:

- Changing the PIP position: “IDTV”

- Changing the PIP size: “16:9”

- Changing the PIP contrast:

- Selecting the PIP frame colour:

- Storing the PIP settings: “OK”

- Not storing the PIP settings: or

PIP Colour/RGB Servicing work after replacing the module:

None.

1: Adjustment of Line Frequency

on the picture tube panel

- Short circuit Pin 5 of IC 5810 (TDA

2579) to chassis.

- Connect a test probe to Pin 17 of IC 5810 (set to 20 msec/div).

- Connect the external trigger input to contact 1 of PIP-colour/RGB module (CCVS signal).

- Set R 5182 so that HA-pulse is no longer sweeping horizontally.

- Remove the short circuit.

2: Adjustments in Chroma Channel

- Feed in PAL test pattern.

- Adjust and to nominal value, to maximum.

- Connect Pin 28 of IC 580 (TDA 4557) to +12V supply.

- Connect Pin 17 of IC 5850 (TDA 4557) to chassis.

- Adjust trimmer C 5783 for stationary pattern in colour bars.

- Remove wire links.

- Connect a test probe to Pin 19 of IC 5520, SDA 9087 (input Y).

- Connect the external trigger input to contact 1 of PIP-colour/RGB module (CCVS signal).

- With PAL-filter F 5773 set the colour carrier of the Y-signal to minimum.

- Feed in SECAM test pattern.

- Connect Pin 27 of IC 5850 (TDA 4557) to +12V supply.

- Connect high-impedance voltmeter to Pin 21 of IC 5850.

- Use filter F 5794 (DL) to align voltage to maximum.

- Remove wire links.

- Connect test probe to Pin 1 of IC 5850.

- Use filter F 5857 (DR) to align zero level of the (R-Y) signal with the line black level.

- Connect test probe to Pin 3 of IC 5850.

- Use filter F 5878 (DB) to align zero level of the (B-Y) signal with the line black level.

- With filter F 5751 adjust the SECAM bell characteristic so that the (B-Y) signal is symmetrical and free of overshooting.

- Feed in 3.58 MHz NTSC test pattern (sound frequency 4.5 MHz).

- Connect Pin 26 of IC5850 to ±12V supply.

- Connect Pin 17 of IC5850 to chassis.

- Adjust trimmer C 5788 for stationary pattern in colour bars.

- Remove wire links.

- With filter F 5761 adjust the 4,5 MHz sound carrier to minimum.

Picture Geometry and Picture Position Adjustment via the Remote Control Handset

For accurate adjustment of the picture a test generator or a standard test pattern should be used. For raster corrections it is also possible to use the integrated test pattern.

1: Call up the Programme Menu with the button

. The indication “Info Centre”

is shown on the screen.

2: With buttons or move the bar to the

menu item “Special Functions” (line becomes red) and activate with the “OK” button.

3: With the button or call up “Service”

and confirm with the “OK” button.

4: Enter code number 8500. 5: With the cursor button or call up the

“Geometry” menu.

6: If a standard test pattern is not available,

move the yellow bar to the menu item “Test Pattern” and switch the integrated test pattern

“On”. Press the “OK” button.

7: Move the yellow bar with the cursor button to

the desired adjustment, eg. “V-Middle”, press the “OK” button, and with the cursor setting

function or adjust for an optimum picture. Adjust the Geometry for the vertical deflection and then for the horizontal deflection.

Attention: it is absolutely necessary to start with the “V-Middle” adjustment otherwise the other vertical deflection parameters would defy correct geometry adjustment.

“V-Middle” Adjustment with a Standard Test Pattern

- For example feed in the convergence test pattern with circle.

- Select the “V-Middle” menu.

- With the button or adjust the rectangles in the upper and lower third of the screen so that they are of equal height.

- With the “V-Linearity” menu adjust the rectangles in the middle of the picture so that their height is identical with the upper and lower ones.

- Continue with the picture geometry adjustment via the menu and store.

“V-Middle” Adjustment with a Video Generator, eg. Grundig VG 1000

- Feed in the convergence test pattern with standard colour bars via RF.

- Call up the “V-Middle” menu.

- With the or button change the setting so that the G-Y vector (orange area in the centre of the picture) is just covered.

- Continue with the picture geometry adjustment via the menu and store.

The “Line Shift” alignment influences the line phase setting. Before this adjustment, set the horizontal amplitude to minimum and if necessary, correct the raster position with the “Shift

Plug”. With the button or move the picture into the centre of the raster. Re-adjust the horizontal amplitude with the test pattern.

8: To store this adjustment, move the bar

to “Terminate with store” and confirm with “OK”.

Attention: The picture geometry is set to the last stored value whenever the receiver is switched on.

Reset:

Under the menu item “Reset” an average data set from the ROM is stored. If the geometry has been aligned wrongly, these basic values can be re-loaded at any time. For this, move the yellow bar to “Reset”. Press the “OK” button. By pressing the “AUX” button the picture geometry is set according to this “Reset” values.

9: With the button return to the normal

menu.

Advice on I2 C-bus Faults

To localise a defect on the keyboard control or a short circuit I2 C-bus on the chassis, disconnect the “MP plug” and switch the TV on with the mains button. The operating unit are indicated correctly. The keyboard control unit does not drive the IC 5010, TDA 9160, in the Colour Decoder Sync (no picture, no sound).

Power Supply Diagram

3GRUNDIG CUC 7880

Control Diagram

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