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How to repair 3.97 inch LCD touch panel? Best Guide

3.97 inch LCD touch panel
One of the biggest problems in multimedia centers is relevant to 3.97 inch LCD touch panel. Generally, they lose sensitivity or get damaged.

In another post, I explained how it works and how to identify resistive capacitive screens. Today I'm going to address a problem that occurs a lot. It happens when there are sudden changes in temperature or the component's useful life is coming to an end.

In multimedia centers, the vast majority of touch screens or "touch screen" are resistive type.

How does the 3.97 inch LCD touch panel problem occur?

In this type of 3.97 inch LCD touch panel technology, when there are sudden variations in temperature, the screen tends to fail or have errors in the commands. Sometimes we touch a certain point but it indicates another, when it doesn't obey.

Due to temperature changes the electrical properties of the set change. This significantly changes the electrical resistance. In this case no need to calibrate the touch screen. Furthermore, this function is available in most of the central multimedia, but in some there is need for specific files.

Why does 3.97 inch LCD touch panel lose sensitivity?

So far so good, the 3.97 inch LCD touch panel problem occurs when the user, thinking that the screen is damaged. He starts to use force. They put extra pressure to the point of the screen breaking. Similarly, its repair cost will be high. Therefore, when the screen “touch” of your control unit presents anomalies follow the tips below:


With a cloth slightly dampened with water, clean the screen.  You can also use products dedicated to cleaning LCD screens.

How to remove dirt from 3.97 inch LCD touch panel?

Note the edges, between the touch screen and the frame, there is a small gap. Over time it can accumulate dirt. You can use a stiff paper (business card) or a 2x folded sheet to pass around the screen and remove dirt;

If there is any membrane, remove it. We do not advise the use of protective films as they damage the touch screen over time.

How to Calibrate the Screen?

After the steps above, check if the LCD touch panel has the calibrate function. Follow the steps described by the manufacturer and use:

  • A pen without ink
  • A cap or a plastic object to make the adjustment
  • Never use your finger to calibrate.

We recommend not to abort the calibrate process. This can cause some problems where only a technician will be able to revert.

Seek Technical Assistance in case you do not fix

If after the above tips the problem is not resolved, send your center to a technical assistance. You can find it near your area.

Attention, avoid squeezing with force as the glass is delicate. And depending on it can also damage the LCD, making the repair even more expensive.

How to fix a magnetized 3.97 inch LCD touch panel?


LCD TV is a TV line with an extremely modern design, manufactured on advanced technology. In addition to the outstanding advantages that beat other TVs, LCD TVs also have many limitations. This also includes LCD touch panel contamination.

  • The cause of the infection from
  • Moreover, the cause of the infection from
  • The cause of LCD TV is magnetized

Because the TV comes near magnetic sources such as electric fans, microwave ovens, air conditioners, etc., this causes your TV to fail very quickly and magnetization is easy to happen.

– Due to the usage habits of TV users, they often control the TV remotely when the TV is in Standby mode, causing the demagnetizing coil in the TV to malfunction during operation, resulting in the TV being magnetized.

How to fix a 3.97 inch LCD touch panel TV?

Steps to fix 3.97 inch LCD touch panel

Method 1: After watching TV, leave the mode completely OFF, so that the TV is not magnetized. Rearrange the position of the TV and the viewing seat for convenience in controlling the TV.

Method 2: Please check the demagnetization circuit to see if it works well. If not, get a fix now.

Method 3: Use magnets to gradually move the magnetically infected areas on the screen, keep doing this continuously until there is no longer any magnetized TV.

Actually, in many cases, there is only old-school TVs. Old ones like CRT are often magnetized, while LCD, PLASMA, and Led are less susceptible to magnetism. LCD touch panel manufacturers have equipped each type of TV with a demagnetization circuit.

3.97 inch LCD touch panel 2021

How 3.97 inch LCD touch panel get damage?

These TV lines often have a demagnetization circuit break due to no power supply. Therefore, instead of using a demagnetization circuit, use a transformer and proceed to the 3rd method to fix the error of the LCD TV being magnetized:

Method 4: Use the transformer to plug into the primary power source, use the transformer to bring back the magnetized TV part, do so until it is effective.

Most common Problem in 3.97 inch LCD touch panel

In the process of using the TV, your TV screen suddenly appears unwanted phenomena. It is a common problem in 3.97 inch LCD touch panel: TVs with screen stripes, Samsung TV pans losing picture, sony TV screen errors, dark TV screens.

These TV pans, if not repaired in time, can cause many other symptoms of illness, causing harm to your TV.

1. LCD, LED, PLASMA TVs have sound but no picture

This problem is very simple. You just need to take some time to check the AV, HDMI connection wires with the Set top box. Check that the AV and HDMI connections are correctly plugged in; you can go online to search for how to connect av, hdmi to the set top box!

2. LCD, LED, PLASMA TVs with picture but no sound:

  1. Check if the AV, HDMI, SPDIF wire connections between the Set top box and the TV are correct
  2. Should you see if the Set top box or TV is in mute mode (sound) or the volume is too low
  3. Activate the “Voice” button on remote Set top box
  4. Or restart Set top box again.

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