Handling Simple Problems in Cable TV Modulators

Please pay attention to the following items for both you and your customers during the use of the equipment:

1： You can choose a satellite antenna to receive programs, a local wired set-top box as the program source, or both can be used simultaneously, or other devices with audio and video output interfaces can be used as the program source. The selection of program sources is very diverse.

2： Connect the video jack of the set-top box (marked with VIDEO in yellow) to the video jack of the modulator (marked with VIDEO in yellow), connect the audio jack of the set-top box (marked with R in red or L in white), and select one of the colors to connect to the audio jack of the modulator (marked with L in red). The channel order is left to right, with the first audio and video jack on the left being the audio and video input for the first channel, the second audio and video jack being the audio and video input for the second channel, and so on.

3： Adjust the program content of the set-top box and arrange the program order according to actual needs, so that each set-top box plays different programs.

4： The internal adjustment and installation of the modulator have been completed, and there is no need to adjust it again. The output field strength of this modulator is around 80db-90db. Please connect the RF jack to the amplifier according to the actual construction site, and the amplifier will amplify the mixing signal and directly connect it to the customer's own cable television network.

5： Installation and debugging personnel should prepare a field strength meter, and when encountering faults, they can check the signal strength of each channel in the circuit. Conduct professional testing on the modulator.

6： The installation personnel should choose the size of the satellite antenna based on the actual situation to avoid situations such as signal instability, no signal on the set-top box, mosaic, etc.

7： Please install and debug personnel to fix and stabilize the satellite antenna to avoid antenna movement caused by weather changes. There is a situation where the set-top box has no signal.

8： Although the manufacturer has designed this product to support low-end set-top boxes, customers are advised to choose a legitimate manufacturer's product when selecting a set-top box.

9： If the set-top box manufacturer comes with a remote control, please retract the remote control to avoid customer misoperation.

(see opposite)

10： It is prohibited to stack all set-top boxes on each layer, which may cause the set-top box to fail to dissipate heat and cause it to crash.

11： Do not hang the power supply in the air. Please fix the power box on the side of the cabinet.

12： Please place the equipment in a well ventilated room to prevent excessive temperature during operation.

13： Please do not work in extremely high or low temperature environments.

14： Do not open the modulator housing without the manufacturer's consent, as the consequences will be your own responsibility.

Common faults:

1： The cable TV line is almost covered in snowflakes, and occasionally there is a station with very unclear programs. Firstly, check if the power supply of the modulator is properly connected. If it is found that there is no red indicator light on the back of each small board, it indicates that the modulator is not working. There is a problem with the power supply of the device. Please check for power supply issues with the device.

2： The power supply has been connected, and all the lights behind the small motherboard are on, but all the programs are still unclear. Please check if the connection wire between the modulator and amplifier is properly connected. Check if there are small shielded copper wires in the coaxial cable that are short circuited or connected to the middle cable. If the connection is normal, please directly connect the modulator output interface to a TV and search for the TV again. If the program is normal, please check the next level of connection and device operation. If the program is still not working properly, please check the chain between the set-top box and the modulator for any issues. Check if the audio and video cable is plugged in backwards.

3： Please note that the amplifier needs to be adjusted. In many cities, installation and debugging personnel believe that cable TV amplifiers can be installed directly, which is very wrong. There are two adjustment knobs inside the amplifier that adjust the amplification. Please refer to the user manual of the purchased amplifier for specific operations. This adjustment is very important for the overall signal quality of the system.

4： After searching for the TV, most of the programs are clear, and occasionally some programs are unclear. Please turn off all devices. Looking at the TV program at this time again, are there any unclear programs? If there are still unclear programs, it indicates that this channel of the modulator conflicts with the channel of the local wireless television station, causing interference. Record this channel number and remove the small motherboard of this channel in the modulator, without using this channel. If the number of channels in the modulator is sufficient for use, skip it. If the number of channels is not enough, please contact the modulator supplier to send back the removed small board and replace it with another channel. Do not remove the small motherboard of other modulators from our company and install it on this modulator without permission, as it may cause equipment damage.

5： After the equipment is connected, some rooms have clear programs, while others have unclear programs. Please check if the distributors summarized in each room are genuine and if there are any problems with the connecting wires. Whether the line distribution is even. Is there a problem with private wiring in the middle of the line.

6： After the equipment is connected, the number of TV search programs does not match the actual number. For example, 24 set-top boxes have been connected, but after searching for programs, 20 were found, and 4 programs were not found. Please label the corresponding channel of each set-top box, place the TV in the computer room, and first adjust the TV to the first channel. Then turn off the power of the corresponding channel's set-top box, and the TV screen will also disappear. This set-top box corresponds to this channel and marks the set-top box. And so on. Find those set-top boxes that were not searchable. Plug the audio and video cable of the set-top box directly into the AV video input of the TV. Check whether the output program and sound of the set-top box are normal. If the screen is black or the program is abnormal, please replace the set-top box and repair it. If the program is normal and the sound is also normal, please check if the audio and video cables connected to the modulator are plugged back in. If the connection is normal, confirm that the program is input to the modulator and search for the TV again. If the program can be found, proceed to the next channel check. If the program cannot be found. Please use the field strength meter to test whether the frequency of this channel is normal and whether the field strength is normal. If the field strength is different from that of other channels, the adjustment knob at the back of this small motherboard can be adjusted slightly. If the field strength can be adjusted to be similar to that of other channels, it can be adjusted. If it cannot be adjusted, please return this small motherboard to the factory for debugging.

7： After the program search is completed, there are some channels that cannot be searched or there is no sound. Some set-top boxes are set to mono at the factory, which means that only L or R has sound on the sound output of the set-top box. When the debugging personnel insert the sound in the wrong position, the modulator system will not recognize the audio. It will adjust the channel, find the corresponding set-top box, and switch the audio jack.

8： After searching for programs on the TV, all programs are clear, but all programs are noisy. This is an automatic recognition error of the TV sound. Please adjust the TV to the first program, select the menu, enter program settings, and enter sound settings. There are many options in the sound settings, and each TV brand and menu are different. Change the sound options until the sound is clear, and then save the settings, If you search again, the sound will be normal. If it still doesn't work, manually adjust the sound of each channel.

9： When the program displayed on the TV shows mosaic, no signal, or the picture is frozen, please check the connection of the set-top box. All the pictures are programs forwarded by the modulator to the set-top box, and some people may mistakenly believe that when the TV picture appears mosaic, there is no signal, or the picture is frozen,