How to deal with the circuit trouble of electrical scale
When maintain, if the check methode is right or wrong to circuit trouble of
lectrical scale, is very important for rapid and nucety to dererminant the
place of the trouble. Overhaul people of electrical scale should in the basic
of familiar with price scale operation and configuration principle, also
should use measure instrument correctly, mastery the basic repair method of
electrical scale. We will introduce to you some common use method to check
the trouble as follow,
1, The intuitionistic method There are a lot of element in the mainboard, some of trouble is induced by short, turnoff, connector does not work well, parts , Hence, when electrical have some trouble, you should use the intuitionistic feeling first: look, listen, smell, touch method to check the circuitry board.
2, Compare,substitute method When checking the trouble, by the help of instrument to make a compare between electrical scales and some problem scales, it will be more easy to find the trouble. In addition, prepare the good sensor, circutry board, power supply, keyboard and so on, if you doubt some part of sensor, circutry board, power supply or keyboard have some problem, you can use the good one to substitute, then observe if there have another result, if showed normal, say that the orenginal element have problem. Compare and subsitute method can judge problem soon and correctly.
3.Voltage measurement
Compare voltage and usual number of circuit element,CMOS chip, the biggest chang of voltage is the place of problem.
4.Short circuit and carve out a way method
Short circuit method is make a part of circuit to be short, then judge the trouble point by oscillograph or result of multimeter testing. Carve out a way method is carve a part of circuit, then judge the trouble point by multimeter test resistance,voltage or current.