Akai Ak2867 Service Manual

AKAI CT 2867 UNT

General Information

Also Covers

CT 2567 UNT CT 2865 UNT CT 2161 UNT CT 2565 UNT

Specifications

Mains power ........................................................................................................... 176-264 V

Power consumption ................................................................................................ ca. 90 W

Stand by .........................................................................................................................0,1 W

...................................................................................................................... 28”/71 cm (110°)

Programme memory loc. ................................................................................................... 99

AV memory locations........................................................................................................... 2

AV memory locations

(CT-25/2867 UNT, CT-2867 UNT DPL) ................................................................................. 3

Sound output ........................................................................................ 2 x 6,5 W RMS (8 Ω)

Dolby Surround: Surround channel Centre channel

Chassis: mains isolated Connections: on the front panel

...................................................................................................................... ≥16 Ω 3,5 mm

................................................................................................................ AV (Cinch/Hosiden)

Connections: on the rear panel Audio out: 0,5 V/1 kΩ

Scart 1/ Scart 2 ................................................................................... Audio in: 0,5 V/10 kΩ

.................................................................................................................Video out: 1 V/75 Ω

................................................................................................................... Video in: 1 V/75 Ω

................................................................................................................ SVHS: Y/C (Scart 1)

...................................................................................................... RGB: 0,7 V/75 Ω (Scart 1)

OSCAR 5 Commander

Aerial................................................................................................................................ 75 Ω

Service Adjustments

Note! Before other adjustments U1 voltage must be adjusted.

Display Note

V.MID-POS. ............................. Adjust centre of the test picture vertical to

................................................. a centred pos. (bottom half is black).

V.TOP-POS. ............................ Adjust top edge (bottom half is black).

V.AMPL. .................................. Adjust bottom edge.

H.SHIFT................................... Adjust centre of the test picture horizontal

................................................. to a centred position.

H.AMPL. .................................. Horizontal amplitude

P.AMPL.................................... Horizontal cushion

P.TILT ....................................... Horizontal trapeze

R.CORN................................... Corner correction (starting SPL21 R 02)

S.COR. .................................... Vertical linearität (starting SPL21 R 02)

GREEN .................................... See adj. “G2- and colour temperature”

BLUE ....................................... See adj. “G2- and colour temperature”

RED ......................................... See adj. “G2- and colour temperature”

ACl........................................... (ON/OFF)SPL70

EQUALIZER ............................ (ON/OFF)SPL70

OSD SHIFT

IN VAR:.................................... (ON/OFF) starting SPL50 R 01

FRONT AV :.............................. (ON/OFF)

LOUDNESS: ........................... (ON)

C4 BIT CHECK: ...................... (ON)

NICAM:.................................... (ON/OFF)

CARRIER-MUTE:.................... (OFF)

VT CHAR: ............................... West / East1 / West Turkey / East2

FLYB MODE:........................... (ON=NTSC) as from SPL21 R02

AGC ......................................... See adjustment “AGC”.

ZOOM ...................................... (ON/OFF)

CORING .................................. (ON/OFF)

Warning!

Service and repair work to be performed only in accordance with existing safety regulations.

X-ray regulations

The picture tube type and the maximum permissible high-voltage ensure that the X-ray intensity within the set remains far below the permissible value. The high-voltage must not exceed 28 kV. The high voltage is within the permissible limits when the operating voltage of the horizontal deflection stage equals 150 V ± 0.5 V (110° 25”/28”), 130 V± 0.5V (90° 21”) or 120 V± 0.5V (90° 17”) at minimum beam current. During servicing, check and adjust this U1 voltage to the nominal value. By following the service adjustments, check and adjust this voltage to the nominal value with R080.

Service mode

Select the service mode by pressing the Mute, OK and TV buttons on the remote control unit. Use the cursor button ▲ or ▼ to select required adjustment and adjust it by using the cursor buttons and . Store into memory by pressing the red OK button. Return to normal TV mode by pressing the TV button.

G2 - and colour temperature

1. Set the TV set to the service mode (see “Service mode”).

2. Adjust the green, blue and red OSD values to 60 with the cursor button or

3. Set the G2 trimmer (RK60) to its centre position.

4. Adjust the brightness to normal level (black bar of the grey scale is black).

5. By using an oscilloscope (Probe 100:1) determine the highest black value at the picture-tube cathodes (R, G, B).

6. Adjust with G2 (RK60) the highest black value to 150 V.

▲

7. Use a colour neutral picture and adjust the light areas in green, blue and red drives to white (lower the OSD valuel with the cursor button or . At least one of the level controls should be remain at 60.

8. Store by pressing the OK button.

9. Return to normal TV mode by pressing the TV button.

AGC

1. Feed in a RF signal (70 dBµV) tuned on a mid range UHF channel and without sound carrier via the aerial input.

2. Set the TV set to the service mode (see “Service mode”).

3. Select the AGC-adjustment with the cursor button ▲ or ▼.

4. Connect an oscilloscope (bandwidth > 50 MHz) to the IF output on the tuner (TL01 or TL02).

5. Press the yellow button on the remote control unit (OSD = OKAY).

6. Adjust the signal to 450 mVpp ± 50 mV. (with reference to the signals synchronizing peaks) with the cursor button or .

7. Store the value in the memory by pressing the red OK button.

8. Return to normal TV mode by pressing the TV button.

U1 voltage

1. Set the contrast and brigthness to minimum.

2. Connect an universal voltmeter to the capacitor C043.

3. Adjust the U1 voltage to 150 V ± 0.5 V (110° 25”/28”), 130 V ± 0.5V (90° 21”) or 120 V ±

0.5V (90° 17”) with the trimmer R080 by black picture.

Focus

Adjust the focus to optimum with the focus trimmer (RK60).

Other service adjustments

Picture reference calibration

▲

1. Press the blue MENU button twice.

2. Activate TV-PROGR option by pressing the cursor button ▲ or ▼ .

3. Enter one of the mid range UHF channels by using the number buttons, e.g. ch. 38 (607.25 MHz).

4. Select the frequency tuning menu by pressing the green button.

5. Select AFC option and change it to ON by using the cursor buttons or .

6. Adjust the frequency to 607.25 MHz with

▲

ZL22 (even with other channels, always set to xxx.25 MHz).

7. Return to normal TV mode by pressing the TV button.

Audio IF calibration

1. Feed in a test picture.

2. Connect an oscilloscope to pin 12 of TDA

2545.

3. Adjust for minimum picture content with the ZL02.

Recommended Safety Parts

Item Part No. Description

RK 55 3151 4519 SRES 1 K 0,25WW RK 56 3151 4511 SRES 2,2E 0,25W RK 60 3722 2010 FOCUS G2 REGULATOR RK 72 3151 4516 ES 100E 0,25W RK 73 3151 4513 RES 10 E 0,25W RO 30 3156 0970 RES 8,2M 0,54W CK 51 3345 0024 SCAP 8,7NF1600V CK 52 3345 0026 SCAP 1,8 NF1600V CK 61 3324 0835 SCAP 27NF 400V CO 01 3345 0004 CAP 0,33MF 275V CO 07 3324 0822 CAP 0,1 MF 250V CO 30 3261 0932 SCAP 2,2 NF 4KV CO 32 3261 0931 SCAP 1 NF 4KV NE 50 3684 1033 PHOTO COUPLE FO 01 4375 1251 FUSE 2,5A T FO 02 4157 0485 FUSE HOLDER TK 60 8681 7340 ANODENCLIP 4MM TK 60 (4870,74,76) 4536 0032 DST ELDOR 1192.6002 NO 1/97 TK 60 (4800) 4536 0031 OST ELDOR 1192.6003 TK 60 (4876) 4536 0018 LINE TRANSFORMER TO 30, 40 4523 1110 TRANSFORMER NE 50 3684 1033 OPTOTCDT 1020G SE 01 4121 0002 MAINSWITCH SAVE PUSH SE 01 4193 0009 CONN CRIPLET XH 01 4155 4034 CRT SOCKET METALLO

(CT2565/2865)

4) 28” 4362 9071 TUBE VID A66EAS13X01

4) 25” 4364 2511 TUBE VIDAS9EAS13X01

8) 25” 4588 0813 DEGAUSSING COIL

8) 28” 4588 0814 DEGAUSSING COIL

▲

15) 4131 4380 MAINS CORD 2,25M UK 4774 0006 HIGH VOLTAGE CABLE

(CT2567/2867)

14) 25” 4364 2503 PICTURE TUBE A59CCY13X01

14) 28” 4364 2803 PICTURE TUBE A66ECY13X01

18) 25” 4588 0813 DEGAUSSING COIL

18) 28” 4588 0814 DEGAUSSING COIL 4131 4380 MAINS CABLE 2,25M UK 4774 0006 HIGH VOLTAGE CABLE

(CT2161)

15) 21” 4364 2104 TUBE90 Vid A51EFS83X191

19) 21” 4588 0811 DEGAUSSING COIL 4774 0006 HIGH VOLTAGE CABLE 620MM 7000 3707 UK POWER CORD + CONNECTOR 2,25m

Specifications / Adjustments / Variable Components for Picture Tube / Dolby Module / SP BG/DK/I Chassis / SP BG/DK/I Chassis Cont’d

SP BG/DK/I Chassis Waveforms / SP Multinorm Chassis / SP Multinorm Chassis Cont’d / SP Multinorm Chassis Waveforms / Safety Parts List

2AKAI CT 2867 UNT

Dolby Module Diagram

Specifications / Adjustments / Variable Components for Picture Tube / Dolby Module / SP BG/DK/I Chassis / SP BG/DK/I Chassis Cont’d

SP BG/DK/I Chassis Waveforms / SP Multinorm Chassis / SP Multinorm Chassis Cont’d / SP Multinorm Chassis Waveforms / Safety Parts List

+ 4 hidden pages