The following are some methods for checking the LVDS cable of a Television:
Appearance Inspection
- Check whether there is any physical damage to the LVDS cable and its connectors, such as whether the outer sheath is damaged, whether the core wire is exposed, and whether the pins of the connector are bent or broken.
- Check whether the connection of the connector is firm and whether there are phenomena like looseness, oxidation or corrosion. You can gently shake or plug and unplug the connector to judge whether the contact is good. If there is oxidation, you can wipe it clean with anhydrous alcohol.
Resistance Test
- Unplug the TV screen LVDS cable on the motherboard side and measure the resistance of each pair of signal lines. Under normal circumstances, there should be a resistance of about 100 ohms between each pair of signal lines.
- Measure the insulation resistance between each pair of signal lines and the shielding layer. The insulation resistance should be large enough, otherwise it will affect signal transmission.
Voltage Test
- Turn on the TV and measure the voltage on the LVDS cable. Generally, the normal voltage of each pair of signal lines is about 1.1V.
- Check whether the power supply voltage of the LVDS cable is normal. For different TV models, the power supply voltage of the LVDS may be 3.3V, 5V or 12V, etc. If the power supply voltage is abnormal, it is necessary to check the power supply circuit.
Signal Waveform Test
- Connect the probe of the oscilloscope to the signal lines of the LVDS cable and observe the signal waveform. A normal LVDS signal is a clean and clear rectangular wave. If the waveform is distorted, the amplitude is abnormal or there is noise interference, it indicates that there is a problem with signal transmission, which may be caused by damage to the cable or external interference.
Replacement Method
- If you suspect that there is a problem with the LVDS cable, you can replace it with a cable of the same model that is known to be in good condition. If the fault is eliminated after replacement, then the original cable is faulty; if the fault remains, it is necessary to check other components, such as the logic board and the motherboard.
Post time: Dec-09-2024
