subject: Pa System Equipment Maintenance Methods - Audio, Black, Home Appliances Common Sense - Hc Network [print this page] 1, visual inspection method Visual inspection method is carried out immediately after disconnecting the power. Without instruments, meters, with an intuitive sense, the mobilization of visual, hearing, smell, touch and other sensory characteristics of 4, to judge. Although the poor accuracy of such examination, but, speed, visual inspection method, particularly useful check on the power failure.
A look at the machine or components and external observation of the structure. View button switches, interface, light availability of loose, then thread whether or off board, whether Weld, discoloration, cracking, spalling and other phenomena, whether the fuse burns out, ignition, smoke, deformation, not stuck and so on, with the eyes, to directly identify and judge.
Two gently flip the machine or parts, swing swing, listen to the scattered availability of parts or screws falling off, whether the rattle. There is no unusual for a continuous turn the "creak" sound or "pops" and ignition noise (power pm). If these phenomena, failure may occur in these areas.
Three press availability with his nose to smell burning smell, smell to find the source of failure could smell the place out a release.
Four touch to feel the transformer housing (after power failure), do not touch the terminal, because there are sometimes charged capacitor, high voltage, affect safety. Feel if this is more than the normal temperature, hot, can not touch. Power management with or without hot or cold phenomena. Whether hot or cold adjustment tube is not hot phenomenon. If these phenomena, the problem may occur in these areas.
Second, heuristicsHeuristics is part of the circuit against suspected comparison, division, substitution, simulation, and testing methods to find the fault lies, and then excluded. Specific methods are as follows:
1, compared with the failure to find a machine exactly the same type of machinery, professional equipment in the same machine using the left and right channel components, measuring the corresponding part of voltage, resistance, current number, then to compare, to find failures.
2, segmentation will be a part of the circuit and other parts of the disengagement, connected to external power, the injected signal, to judge.
3, replace suspect components replaced with good parts, or to the left and right channel components of the change, especially for
IC Block can be carried out. If the components of the change, the machine back to normal, it indicates a problem or damage the components.
4, analog temperature simulation, using hair dryer heating or cooling with alcohol, the temperature performance of inspection, vibration simulation is the use of thin plastic insulating rod light hit certain parts, to see the circuit working condition, can be found some of Weld Phenomena, check failures. This approach generally carried out by technical experts were, they are liable to failure aggravation.
Third, measurement of static parameters Static parameters of the measurement must have a manufacturer's maintenance manual production equipment, indicating the various components endpoint quiescent current, or voltage, use multimeter measuring various parts of the circuit current, voltage or resistance values, to see whether consistent with the nominal value.
1, resistance measurement File with the multimeter's ohm100 or1K file, do not use the R10K file, which file on the internal 22.5-volt battery meter, measured on the transistor inappropriate, easy to damage the transistor. In the case of power measurement, if there is a charged capacitor, must be insulated from the tapered screws after full discharge. Measuring open circuit resistance must be welded at one end, otherwise the measurement is not accurate.
2, voltage measurement
In the process of making this measurement multimeter to consider the impact of resistance on the measurements. Static measurement and dynamic measurement value (by adding signal) is not the same as it should be noted. When the transistor static measurement pin, resistor, capacitor voltage is consistent with the nominal value, the transistor voltage to determine the relative foot pipe for damage.
