This document is a service manual for the TEDELEX EC2975N Colour TV 29-inch, which is built on the M13 Chassis. It also covers models EC2975, EC2575 (25-inch), EC2906, and EC34187 (34-inch).

Function Description:

The TEDELEX EC2975N is a 29-inch color television designed for home entertainment. It supports multiple TV receiving systems including PAL/SECAM, BG/DK/I, and NTSC 4.43/3.58 (AV). The TV features a hyper band tuner and can store up to 100 preset programs (0-99). On-screen display (OSD) is available for menu navigation and function adjustments, with English as the OSD language.

The TV offers comprehensive control over picture and sound settings. Picture adjustments include contrast, brightness, color saturation, sharpness, and tint (for NTSC). Sound adjustments include balance, sound effects (Natural, News, Spatial, and Personal Preference), and a 5-band sound equalizer for individual tone adjustments from 120Hz to 10KHz. Nicam stereo/mono and dual I/II/mono toggling are also supported.

For external connections, the TV provides RF aerial input (75-ohm unbalanced), video input/output (75-ohm 1.0Vp-p, RCA), and audio input/output (10k ohm 0.5 Vrms, high impedance; 1k ohm 0.5 Vrms). It can connect to VCRs, LD players, VCD players, or satellite receivers/decoders. The TV/AV button allows switching between TV programs and AV input sources.

Important Technical Specifications:

TV Receiving System: PAL/SECAM, BG/DK/I
AV Colour System: PAL/SECAM, NTSC 3.58 & 4.43
Tuner: Hyper Band Tuner
Number of Preset Programs: 100 (0-99)
Channel Indicator: On screen display
Function Adjust Indicator: MENU display
Language of OSD: English
RF Aerial Input: 75-ohm unbalanced
Video Input/Output: 75-ohm 1.0Vp-p, RCA
Audio Input: 10k ohm 0.5 Vrms, high impedance
Audio Output: 1k ohm 0.5 Vrms
Audio Output Power: ≥ 6W + 6W
Operating Voltage: AC 230V~, 50Hz
Power Consumption: 130W
Picture Tube: 29" (74cm)
Dimensions (LxWxH): 784 X 505 X 571 mm
Net Weight: 40 kg
Remote Control: Full Function Infrared Remote Control
Effective Distance (Remote): 8 meters
Remote Control Power Supply: DC 3V (two AA size batteries)

Usage Features:

The TV can be operated via both the front panel controls and a full-function infrared remote control.

Power On/Off: The power switch on the front panel turns the TV on or off. The STANDBY button on the remote control or front panel switches the TV to/from standby mode. In standby mode, a red LED indicator lights up.
Volume Control: Volume can be adjusted using the VOL. ▲/▼ buttons. The TV remembers volume settings; if the volume was ≥ 60 before powering off, it resets to 15 on power-on; otherwise, it remains unchanged.
Program Selection: Programs can be selected directly using digit keys (0-9, -/-- for two-digits) or sequentially using PROGRAM ▲/▼ buttons.
Menu Navigation: The MENU button cycles through PICTURE, SOUND, MEMORY, SYSTEM, and TIMER sub-menus. VOL. ▲/▼ buttons are used to adjust settings within menus.
Channel Searching:
- Auto Search: Automatically searches and stores all available programs. Undesired programs can be skipped using the SKIP button on the remote.
- Manual Tune: Allows manual searching and storing of channels. The search direction can be chosen (upward/downward) using volume buttons.
- Fine Tune: Adjusts channel position for optimal picture quality.
Picture Settings: Adjust CONTRAST, BRIGHTNESS, COLOR, SHARPNESS, and TINT (for NTSC) to achieve the most favorable picture.
Sound Settings: Select sound effects (S.EFFECT button) or adjust individual tone levels using the sound equalizer. The SOUND button directly selects the sound system.
System Settings: The COLOR option in the SYSTEM menu allows manual selection of the color system (AUTO mode is default). BLUE BACKGROUND (BB) can be set to ON to display a blue screen when no signal is received. The sound system can also be selected here.
Timer Functions: Includes ON TIMER, OFF TIMER, and RESTRICT TIMER (child lock).
Remote Control Usage: Point the remote towards the infra-red sensor on the main unit. Avoid direct sunlight or strong light sources, and ensure no obstacles block the signal. Batteries should be replaced annually or when erratic operation occurs.

Maintenance Features:

Safety Precautions:
- Electric Shock: Do not open the cabinet. Refer servicing to qualified personnel.
- Ventilation: Ensure adequate ventilation by not blocking openings or placing the TV in an enclosed space.
- Heat: Keep the TV away from radiators and other heat sources.
- Foreign Objects/Liquid: Prevent objects or liquids from entering the cabinet. If this occurs, unplug the TV and have it checked by qualified personnel.
- Mounting: Ensure the TV is placed on a stable, level surface. Do not place it on a cart that is unstable.
- Power Supply: Operate the unit from a household AC230V~, 50 Hz outlet. Pull the plug, not the cord, when disconnecting power.
Cleaning: Use a soft, dry cloth for cleaning. For stubborn dirt, use a cloth dampened with a mild detergent solution, then wipe dry. Do not use abrasive cleaners or solvents.
Condensation: If the TV is moved from a cold to a warm place, condensation may occur. Allow the TV to dry completely before powering on.
Remote Control Battery Maintenance: Replace batteries annually or when operation becomes erratic. Ensure correct polarity. Do not mix old and new batteries or different types. Remove weak batteries to prevent chemical leakage.
Troubleshooting (Picture Problems):
- Ignition: Black spots or horizontal streaks, or picture flutter/drift, may be caused by interference from car ignition, neon lamps, or electric drills.
- Ghosts: Caused by reflected TV signals. Adjusting antenna direction/position may improve reception.
- Snow: Weak signals in fringe areas may cause dots. A special antenna may be needed for extremely weak signals.
- Radio Frequency Interference: Produces ripples or diagonal streaks and loss of contrast.
- CRT Degaussing: If improper color appears due to screen magnetization, power off the TV (or unplug) for 10 minutes, then power on again. Repeat until the color issue disappears.
Service Mode (M13 Chassis Alignment):
- To enter service mode, reduce volume to zero, hold the volume down button on the front panel, and press the display button on the remote controller three times.
- The letter 'D' on the screen indicates factory mode. All changes are stored automatically in the EEPROM.
- Avoid changing system data in the sub-menu accessed by key #7, as it may cause unpredictable behavior.
- Exit normal factory mode by pressing 'Standby'.
- Exit internal factory mode patterns by powering down the set.
- Screen Voltage Adjustment: In D-mode, press MUTE on the remote. Adjust the "screen" VR on the flyback until the horizontal line is barely visible.
- Focus Voltage Adjustment: Adjust the "focus" VR on the flyback until the screen is clear.
- VCO Adjustment: Monitor DC voltage at pin 48 of IC201. Adjust T271 until voltage is 4.62 +/- 0.02 V. Press AFT on the factory remote for automatic AFT adjustment.
- Other adjustments include vertical geometry (V-position, V-amplitude, V-linearity, V-correction, OSD position), horizontal geometry (H-position, H-size, H-parallax, H-corner, H-vertical, H-horizontal), white balance (R/G/B cut-off and drive), and various other system parameters (OSD position, OSD intensity, tint levels, FM/DK NICAM frequency shifts, sub-contrast, brightness, color levels).

Tedelex EC2975N - Page 56

Table of Contents