Several common faults and maintenance methods of multimedia active speakers

Sofa butler speaker multimedia active speaker is the computer used to sound the main equipment, technical content is relatively reduced, but there are still many types of failures, such as our common power failure and power amplifier failure, etc., how to repair such problems encountered What? Below, the author will share with you some of the common types of failures of multimedia powered speakers and how to deal with them. I hope to help you repair active speakers.



Fault 1, power failure

Part of the power supply fault is generally found in transformers and rectifier circuits. There are transformer short circuits, fuse breaks, rectifier breakdown, etc.; fault phenomena are silent or large commutation sounds, and the most damaging is the short circuit of the transformer, which causes the transformer temperature to rise sharply. Until it burns, it even triggers a fire in the cabinet. If the rectifier tube is broken through more than two short circuits, it will also cause a short circuit in the transformer.

Solution: Turn off the speaker power immediately when the sound box is suddenly silenced. Transformer only need to change the same model, rectifier can generally be directly replaced, the fuse is more easy to burn, change one can be.

Detection ideas: Disconnect the positive and negative power output terminals first, and measure the transformer secondary output AC12V normal. Check D1 ~ D4 separately for normal, no short circuit breakdown, open circuit and other phenomena. Then measured C36 voltage +15V normal, while the measured voltage across C37 is between -10 ~ 15V swing observed c37 a pin off, welded back to the power input test machine, the machine back to normal.

Fault II. Power amplifier failure

If the fault is in the amplifier part, then the phenomenon is more: there are hum, no sound, only one sound channel, loud noise and so on. Because most of the speakers now have integrated power amplifier functions, the circuit is relatively simple, and the power amplifier blocks are generally fixed on the metal back plate behind the speaker, which helps heat dissipation and is also very easy to find. If the amplifier block fails, the temperature will rise rapidly after power on, so the metal back plate will be very hot and even hot.

Solution: Solve this kind of problem to replace a power amplifier block can generally be solved.


Fault 3, speaker sound is not normal 1, the speaker is generally not possible to burn all units of high, medium and low sound, so if the sound is silent, please check the VOD, preamp, power amplifier if there is a problem, determine and then check the speaker.

2. The speaker emits an abnormal sound of “BU Bu”.

Solution:

1), open the box net, check whether there is leakage of the box, the unit is firmly installed on the box (sometimes the unit is not fixed, high power and dynamic use of the iron edge of the unit and the box will also collide A strange leak sounds. If each unit is firmly attached, listen carefully to the unit from which the abnormal sound was sent.

2) Remove the unit with abnormal sound, place the unit flat on the ground, check whether the bubble is broken and degummed, and whether the dust cap is degummed (usually the “bub” sound is related to the above reasons). If there is no degumming and leakage, then use the right finger to balance the triangle downwards and press the unit's paper tray naturally. (When the normal unit pushes down, there should be no noise, and the edge and voice coil are deformed. The unit will emit unusual noise.)

3) If the unit is not firmly installed noise, re-installation can be firmly, if the unit bubble or dust cap degumming leak, with agricultural machinery plastic (roadside make-up shoes with glue) sealed up to dry naturally.

4) Check whether the contact point between the speaker grille and the box is free of foam rubber buffer strips. If no, then apply plastic strips to remove the noise.

5) If the speaker unit is burned out, it should be returned to the factory for repair. Because the voice coil and paper cone will affect the tone, if you do not use the original voice coil and cone, the horn sound will change.

The above three types of failures are the most common of all failures of multimedia powered speakers. If you have mastered the maintenance methods for these failures, then repairing active audio sources is not difficult for you.

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Guangzhou Ehang Electronic Co., Ltd. , https://www.ehangmobile.com