How to check the PTC on TV: how to repair

PTC - one of the parts of the system, which is responsible for demagnetization. At high magnetization, the TV image is distorted or stripes appear. Their appearance indicates that the device is out of order. You need to check its performance. If necessary, repair or replacement of PTC.

How to check the PTC on TV

PTC thermistor and a resistor - elements that are able to change their resistance when heated. Resistor has been a slight rise in temperature. Posistor same blocks supplied thereto a voltage, so its temperature can rise much.

To check on the performance of PTC, it is necessary to define the characteristics that are considered standard at work. If these deviations are seen, then it broke down. Characteristics are as follows:

1. Nominal resistance. This condition works only at normal room temperature (not less than 18 and not more than 27 degrees).
2. The resistance is determined by the point that characterizes the relationship between resistance and temperature changes in the room. This option is with increasing resistance doubled relative to the standard value.
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3. There is a certain maximum voltage. If you exceed it, there is a risk that the equipment will break down.
4. current load parameters are divided into several types. Among them: the nominal switching, high and rollover. They are essential if the PTC will be used in the scheme of high accuracy.

Attention! Before checking the item, you must wait until it cools down to up room temperature.

What troubles you might encounter pharmacist

To determine the presence of faults in the element can be seeing a distorted image on the screen. This means that the element is strongly magnetized. Workarounds, connecting grid series with the device. Grid - an external loop which covers the inner surface of the screen.

PTC often soldered to the screen. So check it is not disconnected from the TV, it becomes very difficult. To perform the measurements, it is necessary to unsolder at least one part of the device from the grid. But the best solution would be a complete extraction of the device from the system.

PTC Heat can be a simple hairdryer. To test the functionality of the device, without heating it externally, you must assemble an electric circuit. This will help determine the type of device. The instructions should be written for any voltage element operates, and what temperature it can withstand.

Can determine serviceability of the device, heating it with a hot air gun. If you noticed an increase in resistance, so the cell operates. But this method has the disadvantage test - the results can be misleading. The problem is that the resistance of parts assembled circuit can change with time, and so they start to behave erratically.

Another way to determine the fault PTC - the distortion of the image. It can ruffle, or are extra bandwidth. Determine the cell efficiency is possible by using a multimeter. It is recommended that PTC was cold, because the heat resistance is growing.

Another problem - the contacts fall off. With constant heating PTC, they begin to wear out, and as a result are eliminated. Contacts may appear to look okay, but not to work. Determine their efficiency is possible by means of an ohmmeter.

If the PTC is broken or short-circuited, the first time you turn on the TV will burn the fuse. If the network has not happened a short circuit, you must turn off the PTC and check if it works.

Attention! It may be damaged not the PTC, and the element that is responsible for its cooling. We carry out checks.

How to repair

Find the device is simple, it is located behind the back cover, near the fork, which includes the loop degaussing.

If the reason - the magnetization device, it is necessary to demagnetize. For this unit sealed off from the TV and connected to a degaussing system.

But in most cases, damage to the unit require replacement. It is necessary to unsolder the old, and to solder a new, similar in characteristics. If we choose the wrong device, it will not work.