Skip to main content

Philips 21PT9457 55 – Flat CRT TV Circuit diagram and adjustments


This chassis does not contain a specific Service mode. The Services and device setting can be made via Mode the Technical Assistance Factory.
There is no program on TV
Check method: Check the closed circuit to the tuner IC image encoder for detecting whether components defective. Or check if the resistance R117, R118, R203 and R204 has increased may cause the problem.
No Good Picture or Dual Image
Check the signal IF1 / IF2 to Q101 and relevant circuit. In this case the problem can be Q101 and / or SAW 101.
No Picture or Color Correct
• Check the circuit IC201 to RGB.
• Check the welding IC and physical damage of the relevant circuit or check defective capacitors.
Image with White Line Horizontal and Audio
Check voltage supply of vertical IC301 and circuit relevant, and check the vertical sync signal IC201.
Control Evil Operation Remote
Check voltage at pin 64 of IC201. The normal value should be 5.15V. If correct check the welding connections front control panel. If it cannot be resolved check remote control, remote transmission or crystal diode are in good condition.
Without audio
Check audio power IC (IC402) and relevant circuit.
Check BTSC panel, the power of the IC801 and signal output pins 21:27 this IC. Do not delete the IC801 and / or IC402 may be faulty. If necessary, replace the speakers.
Bad Quality Audio
Check the audio system after searching the channel that should be NTSC or AUTO. If the problem persists, check the panel circuit is good chassis or not.
Main voltage adjustment
To adjust the main voltage, connect a voltage meter the diode D610 and cathode VR601 adjustment to the voltage 110 V + -0.3V.
Circuit diagram (Schematic) and PWB [Click on the pictures to magnify]
SMPS (split)
Sub-woofer
Block diagram
Adjustment mode flow chart
Factory Mode adjustment procedure
Software settings
Place evenly-matched in the MENU mode (the default mode) as follows (see "Factory Mode" figure on the next page:
> Press the [i +] keys, "smart sound" and "smart picture" for enter the factory menu.
> Press the [i +] again and "ADJUST" appears on screen.
> Press the number keys to enter the set page, press the Up/Dn keys to change the items that have been set, press the Left/Right keys to adjust their values .
> Press [i +] to exit the factory mode.
The different parameter settings are described above.


Comments

Popular posts from this blog

Electronic Extended Play Circuit Diagram

This is a Electronic Extended Play Circuit Diagram. A single op amp-one of four contained in the popular LM324-is operating in a variable pulse width, free-running square wave oscillator circuit, with its timed output driving two transistors that control the on/ off cycle of the tape-drive motor. The Oscillator` s positive feedback path holds the secret to the successful operation of the variable on/ off timing signal.   Electronic Extended Play Circuit Diagram The two diodes and pulse width potentiometer R8 allows the setting of the on and off time, without affecting the oscillator`s operating frequency. One diode allows only the discharge current to flow through it and the section of R8 that it`s connected to. The other diode, and its portion of R8, sets the charge time for the timing capacitor, C3. Since the recorder`s speed is controlled by the precise off/on timing of the oscillator, a simple voltage-regulator circuit (Ql, R3, and D4) is included.  Connecting the spe...

Power Amplifier with voltage regulator 4 × 50 Watt TDA8588

Power Amplifier with voltage regulator 4 × 50 Watt TDA8588    The TDA8588 is a multiple voltage regulator combined with four independent audio power amplifiers configured in bridge tied load with diagnostic capability. The output voltages of all regulators except regulators 2 and 3 can be controlled via the I2C-bus. However, regulator 3 can be set to 0 V via the I2C-bus. The output voltage of regulator 2 (microcontroller supply) and the maximum output voltage of regulator 3 (mechanical digital and microcontroller supplies) can both be either 5 V or 3.3 V depending on the type number. The maximum output voltages of both regulators are fixed to avoid any risk of damaging the microcontroller that may occur during a disturbance of the I 2C-bus. The amplifier diagnostic functions give information about output offset, load, or short-circuit. Diagnostic functions are controlled via the I2C-bus. The TDA8588 is protected against short-circuit, over-temperature, open ground and open VP ...

Siemens LOGO PLC Ladder Programming Steps

Siemens LOGO PLC Ladder  Programming Steps  Following are Step by Step instruction to Program Siemens Logo PLC Siemens Logo PLC Click on “ Siemens LOGO ” Click on “ siemens rse ” Click on “ StartLOGOComfor t” Wait… You will find the work pad where you have to write FBD programme Use “menus” given at the top and bottom to develop a FBD programme. Find Tools toolbar, Standard toolbar, Menu bar and Status bar. Entering a New program : Click on “ File ”               “ New ”               Create a program using Toolbars and Function blocks (Constants, General and Special functions) • You can then place any of those functions on the drawing board simply by clicking on the drawing board in the desired position. The function on the extreme left is selected by default but you can select any of the others by clicking them with the mouse. • It is not necessary to position the objects precisely at this point. • To ...