2. Silent failure
The silent failure is characterized by the inability of the system to output any signal, despite the fact that the functional keys are being operated with a corresponding state。
In repairing such failures, we need to focus first on protecting circuits for amplifiers. When you turn it on, you have to look carefully at the movements of the protected relay. If there is no movement, then we need to further measure the mid-point output voltage of the power discharge circuit and the overflow detection voltage to determine whether the power magnification circuit is malfunctioning。
If the mid-point output voltage is offset or overflow detection of voltage abnormalities, this usually means power magnification circuits are problematic. At this point, we should check that positive and negative power is working. If positive and negative power voltage is asymmetric, we can further judge whether the problem is whether the power circuit itself or the power-discharge circuit。
If the power discharge circuit is normal, but the protection of relays is still not adsorbed, the problem may arise in protecting the circuit itself. We need to check whether relay-driven integrated circuits or drive tubes are damaged and check whether circuits are functioning。
3 light
Acoustic light failure means a reduction in amplifier gain or output power as a result of a significant change in the deployment of an amplification level or decline in a link during the magnification transmission。
During the overhaul, the normality of the signal source and the soundbox should first be confirmed, which can be checked through substitution. It then examines all types of conversion switches and control bits to see if they can increase the volume。
If there are no anomalies in any of the above, a further determination will be made as to whether the fault is at the front or the back level. In the case of a low monosound, an attempt can be made to exchange the signal from the front circuit to the back circuit of the other channel. If the sound size of the speaker remains unchanged, the failure is at the later stage; otherwise, at the front level。
The lightness caused by the back-up magnification circuits may be due to insufficient output power and gains. The specific reasons can be determined by adding the input signal. For example, the signal output of the recorder to the speaker is added directly to the input end of the back-level powered circuit and changes the volume of the recorder to observe changes in the output. If the output sound is large enough, it means that the gain is low and that elements such as the relay contact point, the input of coupling capacity, etc., need to be checked; if the sound is distorted and the volume does not increase significantly, the output power is insufficient and the performance of the amplifier is checked for positive and negative power voltage, power tubes or integrated circuits, etc。
The light of the sound caused by the conversion switch in the front circuit, the bits, etc., can normally be detected and repaired by visual inspection, such as cleaning or replacement. In case of suspicion of failure of signal coupling, it may be tested with the same amount of condensation; in case of poor performance of magnifying tubes or transport of integrated circuits, it may also be checked in substitution. In addition, the problem of negative feedback components may lead to a decrease in circuit gain, which requires careful inspection。
Six, output squeaks
Shouting failures are the result of motorization in the circuits, divided into low frequency and high frequency. Low frequency whistling is called a low frequency "sing" or "doing" which is usually caused by power filtering or decoupling, and requires checking whether the power filtering capacitors, voltagers and decompressors are open or ineffective. The temperature of integrated circuits increases when the performance of the integrated circuit is poor or when low frequency squeals are triggered。
The high frequency squeals are associated with the failure of the high frequency defibration on the magnification circuit or the deterioration of the performance of the front stage discharge integrated circuits. At the end of the overhaul, a second-level magnification circuit can be tested for the retrenchment or withdrawal of the capacitor at both ends, followed by a small cap. In addition, negative feedback elements are damaged, variable or welded, causing high frequency positive feedback and resulting in high frequency squealing。
For the overhaul of the ocl discharge circuit, care needs to be taken of the characteristics of the non-output capacity to ensure that the dual power supply is symmetrical. When power problems are eliminated, the damage element may be replaced gradually and the point voltage and resistance measured until the output end voltage is virtually zero. When the test is conducted, a large power tube can be installed and repaired using another acoustic reference, if there is no distortion and the component is not abnormally hot. If there is uncertainty about the quality of the repairs, the high-capacity high-pressure output caps at the output end can be protected。
The company's long-standing commitment to the maintenance of specialized audio equipment is derived from the quality of maintenance guaranteed by the original plant, its strong technical capacity and advanced maintenance detection equipment to ensure maintenance efficiency. Specializing in the maintenance of stage acoustic acoustic modifications to the technical guidance for the commissioning of home-based acoustic acoustic circuits, ... Heart service is the slogan of our service, and we offer you a very thoughtful service and a large number of users are welcome to call. Service commitments: first inspection, negotiation, repair, failure to fix at no cost, and when the service is completed, the technician leaves a warranty, and the customer association leaves it to the client as a warranty to address the customer's concerns and ensure that the client is satisfied. 62 mid-level technicians and 98 senior technicians. The recovery rate for the use of spare parts from the original plant was achieved. It's a perfect machine。
