Hongzhao Innovation Electronic Co. Ltd.

The common failure of the building intercom

Symptom 1: System out of function
1. The whole system is out of function
Possible cause: Whether the power indicator light is on or not.
Whether the power of the principal machine or distributor is wrongly switched on, or there is short circuit.
Method: When the indicator light is off, please get through the power supply cord correctly.
Otherwise, the fuse wire is burnout which need altering.

(Remark)
A: Building Intercom System with Floor Platform: Please check whether the intercom is well functioning or not ( the intercom quality and connecting wires around). Then, please check whether the power supply is OK( the power supply quality and the wires around); Lastly, whether the the floors are well preserved ( the platform quality and the wires).

B: The Building Intercom System without floor platform: Please check whether the intercom is well functioning or not ( the intercom quality and connecting wires around). Then, please check whether the power supply is OK( the power supply quality and the wires around); Lastly, whether the indoor device is normal( the device quality and the wires around as the quality of the indoor device would greatly impact the stability of the system).

2. Calling but no video
Possible cause: Whether the circuit of the 18V video power supply is wrongly connected?
Method: Connect the power supply correctly－－Video distributor－－Indoor device power cord.

(Remark: Please firstly check the video wire of the indoor device, then the power supply and lastly the quality of the indoor device)

3. Calling defective while video standby but no image
Possible cause: Please check whether there is 12V output for the power supply, and 12V input for the outdoor device.
Method: If there is no 12V output, please alter the fuse of the power control or change the power supply directly. Otherwise, please connect the power cord between the device and power supply correctly.
(Remark: These kinds of fault are mainly caused by the circuit, and then the quality of device.)

4. No vibrated ringing when calling but image and speaking
Possible cause: Please check whether the circuit from outdoor device to the No.1 sub-device (remark: marking varies from manufacturers) is correctly connected , whether the device is well-functioned and the receiver is in place.
Method: Make use of another device that is well-functioned to check whether it can works. If not, please check whether the circuit is wrong.

5. No ringing or image in the extension while ringing in the principal when enter the floor number and room number.
Possible cause: The floor number is not ready in the decoder or mismatch.
Countermeasures: Please identify the floor number in the decoder and distinguish the represented room numbers for the terminal and lastly plug in the wire correctly.

Symptom 2: Conversation problems
1. All user extension can not bilateral talking
Possible cause: Please check whether the extension audio wire for the outdoor device and the decoder and the one between the decoder to the user extension ( line 3,5) is wrongly connected.
Countermeasure: Please connect the transmission wire based on the specification.
2. Certain user extension can not conduct bilateral speaking
Possible cause: Please check whether the extension audio wire between the outdoor device and the decoder and the one between the decoder to the user extension ( line 3,5) is wrongly connected.
Countermeasure: Please connect the transmission wire based on the specification.

3. Current noise when talking
Possible cause: Please check whether there is interfering source or the audio wire is correctly connected.
Countermeasure: Please connect the wire correctly or replace the power supply to have a try.
Symptom 3. Unlocking malfunction
1. All the user can not conduct the unlocking
Possible cause: Please check whether the outdoor device to the power supply or to the E-lock is well connected. Please check whether the circuit for unlocking is well connected( Line 2 for pressing pattern while Line 3 for digital pattern)
Countermeasure: When well connected the wire, the unlocking can be conducted through password, then the E-Lock is well-preserved. Please check whether it can be unlocked when getting through the main line to decoder.
2. Some user can not unlock the door
Possible cause: Please check whether the unlocking wire is disconnected or poor-connected (Digital system: line 3 from extension to decoder; Pressing mode: Line 2 from extension to the outdoor device) and check whether the device is well-functioned.
Symptom 4: Video Image
1. Snowflakes noise
Possible cause: Please check whether the 18V video power is misconnected to the outdoor device which led to overheat of the camera.
Countermeasure: Please connect the wire correctly.
2. No full image
Possible cause: Please check whether the extension is under 18+/-1V
Countermeasure: Please check whether it is too far from the extension to the power supply and whether the power cord is standard.
3. No full image
Possible cause: non-synchrony due to to weak signal
Countermeasure: Please check whether the audio wire is well-connected and the transmission distance is too far or the wire is standard or not.

4. Vague Image
Possible cause: weak signal, impedance incompatible or low contrast ratio
Countermeasure: a) Please modulate the 75Ω impedance switch of the back.
B) Modulate the potentiometer to improve the image quality when low contrast or brightness.
5. Raster but no image on the video extension
Possible cause: If there is no image for the video extension of the whole building, please check whether the polarity has been reversed for the connect wire of the outdoor video output V to the first level video distributor. Whether the distributor has been switched on and the port for the in/output has wrongly been connected.
Countermeasure: Switch on the video distributor and connect the in/output video cable correctly.

Those issues mentioned above is just a one-side analysis, we should be based on the actual case to deal with.