In this case, check the following items in turn:

• Wait a minute, and re-select "Search Devices", then click [Apply] button, we suggest user repeat this operation for several times. If the screen does not display the abnormal message as shown in Figure 2 or Figure 3, it indicates that the previous displayed "abnormal communication" is actually resulted from the interference of communication.
• Check the connection between main emitter box and COM port of PC, power cable and antenna.
• Check if the green indicators on the panels of all probe rods are light on; if not, charge the batteries of the probe rods.
• If all the above items are normal, it can be basically judged that the main emitter box of radio is failure. Replace the main emitter box of radio.

If the #6 and #8 video communication group is abnormal, the screen will display an interface as shown in Fig 3.

 In this case, check the following items in turn:

• Wait a minute, and re-Select "Search Devices", then click [Apply] button, we suggest user repeat this operation for several times. If the screen does not display the abnormal message as shown in Figure 2 or Figure 3, it indicates that the previous displayed "abnormal communication" is actually resulted from the interference of communication.
• Check if the green indicators on the panels of RR probe rod is light on; if not, charge the batteries of the probe rod.
• Check the connection between main emitter box and COM port of PC, power cable and antenna.
• If all the above items are normal, it can be basically judged that the main emitter box of radio is failure. Replace the main emitter box of radio in the probe rod.

• The camera is warded off by any object while testing;
• The system is disturbed by other infrared light;
• The settings is changed on  "Video Proc Amp" page, after clicking [Video Capture Filter...] button;
• Failure LED or low battery voltage;
• Fireless communication interfered;
• Video signal disturbed;
• Poor or failure video emitter circuit of video box and/or probe rod.

Firstly select "Close All" item, and then click [Apply] button.
Then select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  

Select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  If the image calibration interface becomes black screen, the possible causes are:

• The light is blocked between #1 camera and the opposite infrared LED;
• The wheel clamps or the probe rods are not properly installed;
• The vehicle alignment parameters are over the testing range of KWA-521;
• The wheel clamps or the probe rods are crashed.
• The settings is changed on  "Video Proc Amp" page, after clicking [Video Capture Filter...] button;
• The opposite infrared LED of #1 camera is failure or poor circuit.

Solution:

• Take away the object that block the light between #1 camera and the opposite infrared LED;
• Reinstall the wheel clamps and probe rods;
• Repair the vehicle and then perform wheel alignment;
• Open the probe rod and check the camera, re-position the camera as required;
• Click [Video Capture Filter...] button and enter the "Video Proc Amp" page. Set the contrast value to about 7000 and other values to 0. The actual value for each device is set well; user should not change it;
• If the LED circuit of the probe rod opposite the camera is normal, replace the infrared LED.

Select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  If the image calibration interface has more than one bright dot (or images), the possible causes are:

• There are infrared LED images in the testing area;
• Other infrared light enters the testing area;
• The settings is changed on ”Video Proc Amp” page, after click [Video Capture Filter...] button.

Solution:

• Block the reflector of the infrared LED;
• Move away or block the infrared light;
• Click [Video Capture Filter...] button, set the contrast as about 7000 and other parameters as 0. (Please enter the standard values for each device and don't change them at will). If the displayed values are not accord with the standard values, please set them as standard values as shown in Fig 5.

Select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  If the bright dot on the image calibration interface is too small, too large or too dark, the possible causes are:

• The infrared LED is failure on the opposite side of #1 camera;
• The settings is changed on  "Video Proc Amp" page, after click [Video Capture Filter...] button;
• The position of the camera or the LED has changed after crashing.

Solution:

• Check if the infrared LED circuit is normal; if so, replace the corresponding LED.  
• Click [Video Capture Filter...] button, set the contrast as about 7000 and other parameters as 0. (Please enter the standard values for each device and don't change them at will). If the displayed values are not accord with the standard values, please set them as standard values as shown in Figure 6.
• If the problem still exists after finished above steps, it indicates that the position of the camera or the LED has changed after crashing. In this case, please re-calibrate the probe rod.

Select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  If the number of bright dots is less than specified number, the possible causes are:

• The light between #1 camera and its opposite infrared LED is blocked;
• One of the opposite infrared LED or its circuit is failure.

Solution:

• Take away the object that block the infrared light;
• Check the connection of infrared LED; if it is normal, replace the infrared LED. 

Select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  If the image on the image calibration interface scratched, the possible causes are:

• The battery of the corresponding probe rod is under voltage;
• The video communication is interfered;
• The video emitter of the corresponding probe rod is abnormal.

Solution:

• Check if the battery voltage indicator is green on the panel of the corresponding probe rod; if not, charge the probe rod.
• Wait a moment; watch the "sensor calibration interface". If the displayed image is normal, it indicates that the cause for abnormal image is resulted from interference of the video communication.
• Firstly open the plastic cover at the middle of the probe rod, check the connection of the emitter and antenna; if the connection is normal, replace the emitter. 

Select "#1" and "on" item (select "#2" and "on" for image #2 and so on), and then click [Apply] button.  If the image calibration interface is blue, the possible causes are:

• The video receiver box is abnormal;
• The video pick-up card is failure.

Solution:

• Check the video connection between the video receiver box and video pick-up card in the PC;
• Check the power connection;
• Check the antenna;
• Replace the video receiver or the video pick-up card to see which one is failure.