Analysis and maintenance of DVI Interface Circuit DVI interface introduction.

Last Update Time: 2019-11-23 10:27:30

      The DVI interface (see figure 1) is an interface for transmitting digital image signals, which is used on some motherboards. DV-D and DV-I are used on some motherboards. The DVI-D is a pure digital interface, while the DVI-I interface has a digital signal and an analog signal output. DVI conversion head can be used to convert the output VGA signal. 


Fig. 1 physical diagram of DVI interface.


      The working principle of DVI interface.

       The DVI-I interface circuit is shown in figure 2, and the DDPB_HP is the DVI interface hot-swappable identification pin.        When the DVI interface is attached to the monitor, the monitor sends out a 5V or 3.3V high-level signal to the graphics card circuit on the main board, then converts it to the DVI control module inside the North Bridge chip (see figure 3), and the North Bridge chip from the IC bus DDPB_SCL, Read the display DDC data on the DDPB_SDA, after reading the DDC data, adjust the video signal inside the North Bridge chip until the parameters such as the resolution of the video signal are consistent with the required parameters of the monitor, and then transmit it to the DVI interface. The DVI-TX0~DVI_ TX2 cable via the DVI interface is sent to the monitor for display.

      Troubleshooting method of DVI interface.

   1.Visually inspect the interface for damage.

           2. Measuring whether the DDPB HP voltage of the hot swappable signal is 3.3 V.


Fig.3 DVI interface identification.


             3. Measure whether the DDPB_SCL,DDPB_SDA of the Ic bus is normal.

             4. Test the data line DVI_TX, DVITX- to the ground if short circuit, open the circuit.

             5. If the above conditions are normal, weld the North Bridge chip first, and then replace the North Bridge Chip if there are still faults after welding. 

If you want to know more, our website has product specifications for DVI Interface Circuit DVI interface, you can go to ALLICDATA ELECTRONICS LIMITED to get more information