Jumat, 10 Februari 2012

TV repair

Let TV repair done carefully and thoroughly as it can be fatal. Television is an electronic plane that has a high electrical voltage. In addition, of all the damage is not necessarily caused by the faulty component. Sometimes damaged due to poor solder tin so that the legs of components are not perfectly connected to the PCB. Symptoms and causes damage to various TV. The symptoms can be totally dead, no sound or picture produced ugly. Meanwhile, the damage can be caused by a TV that has component with age or relationship between the components is less than perfect

There is some damage that could lead to a TV set can not work at all. In general, this kind of damage occurs on the power supply (Power Supply) or the horizontal deflection circuit
What is the total dead TV and indicator lights go out?
Cause: most likely damage the power supply circuit
Solution: check the grid, a series regulator input to output
Consider the following regulator circuit schematic drawings. In general, TV has a power supply output voltage of 115 V, 24 V and 5 V, depending on the brand of TV. Replace damaged components and improve the circuit path is less than perfect. The arrows indicate the components that are easily damaged.

Is audible squeal vibration transformer switching?
Cause: The output voltage is usually blocked because of a faulty component. Solution: Remove the burden of the regulator by disconnecting the output transistor base horizontal or one foot horizontal transformer and measure the output voltage. If the output shows the voltage regulator in accordance with the instructions on the PCB, check that all the distribution channels of the output voltage regulator and a whole set of horizontal.

Consider the following horizontal circuit schematic drawings. In general, the usual components are easily damaged flyback transformer, horizontal transistor and a capacitor (see arrows).

Raster is not brightly lit screen even though the position of the maximum flyback.

Cause: The CRT anode voltage is too low due to the damage to the high voltage circuit, horizontal deflection circuit or power supply circuit. CRT cathode voltage all became great because of interference with the video amplifier. Solution: Have voltage regulator output is normal? If normal, check CRT cathode voltage. If not normal, check the regulator output voltage. Is the CRT cathode voltage normal? If normal, check the CRT anode voltage. If not normal, check the high voltage circuits.

Raster A Horizontal Line

Sources of interference depends on the oscillator used TV.

Solution: Check the vertical deflection circuit IC Check all electrode or a transistor with multitester.

Horizontal synchronization Bad
Black strips can not be lost even if the synchronization of the raster set.

Such damage is rare for a new TV output. If the damage happens, usually caused by a component that has been ingested age.
Check the horizontal oscillator circuit. The possibility exists that Elko is dry. Elko is usually indicated by the back that looks dull or broken.

Vertical synchronization Bad
Damage lies in the integrator or the vertical oscillator circuit. Such damage is usually common in an older TV. Solution:
Check the vertical oscillator circuit. TV vertical output regulator may long have worn, while the new TV damage caused by leaking ceramic capacitors.

The screen image narrows
Damage like this rarely happen on TV the new output. Lower voltage so that the horizontal output circuit current in the sawtooth horizontal deflection coil (yoke) to grow weak. Solution: Check the power supply output voltage. If a lower output voltage, check the components. Check the horizontal deflection circuit transistor is mainly present in it. Check the condition of the yoke, if it is damaged or frayed should be replaced

Horizontal Deflection Transistor
Widening the Horizontal
Such damage is caused by a defective Vr. Solution: Check the components. If the normal power supply voltage, check the CRT anode voltage If the CRT anode voltage is too low, check the circuit Change the value of VR, if no change in the VR switch. Check the power supply output voltage. If the output voltage is larger high-voltage amplifier.

The Top Or Bottom depreciation

Due to the value of Vr is not appropriate or electrolytic capacitors are dry.
Solution: Set VR, if no change in mean VR is broken. Check Elko are still good or it is dry
Image Vertical Aft
Sawtooth currents on the vertical deflection coil is too low. solution:
Adjust VR, if nothing changes it may Elko is dry.

Snow Noise Figure
Cause: The field intensity at low frequencies where the signal reception. Broken TV antenna system of high-frequency amplifier circuit is damaged Solution: Rotate the antenna to get good pictures. Fix path Check the antenna cable and solder the tuner AGC block.

Low Contrast Images

The damage is located between the mixer to the amplifier circuit video.
Check that there is a resistor whose value is enlarged or short.

Black Horizontal lines
Usually caused by a device that uses a small motor. solution:
Keep away from sources of noise of the TV.

Disturbed by Channel Picture Other
Cross-modulation occurs by a channel that has a large emittance. Solution: Adjust the TV antenna height Set the value of Vr AGC circuit

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