Electronics technology hardware in

deep maintenance personnel and maintenance work full confidence. Improper work together still less effective. Then what to do to better improve maintenance efficiency?
This is several principles to be discussed below for reference. maintenance work methodically carried out systematically by order.

The principle

: look after amount
treat the repair circuit board first should be visually inspected. Necessary, but also through the magnifying glass.
See:
1. disconnection and short-circuit at; circuit board PCB cable, the existence of phenomena such as breaking adhesions; - 2. relevant components such as resistors and capacitors inductors diode transistor disconnect phenomenon exists;
if anyone repaired? move which components? whether there are anti Weld leakage welding plug inserted in the wrong.

Exclude the above situation, this time the first measurement the resistance usually circuit board circuit board between the power and ground resistance with a multimeter should not be less than 70Ω if the resistance is too small, only a few dozen ohms description of the circuit board components breakdown or partial breakdown must take measures to find out the breakdown of the components. specific method for to repair plate power (Note! must find out the operating voltage of the board unacceptable voltage value and the polarity wrong and join points higher than the value of the operating voltage. otherwise will be treated to repair circuit boards have hurt! old fault did not rule out another increase in new problems!!) temperature measurement circuit board device temperature rapid temperature rise higher as focus of resistance to normal and then with a multimeter measurements the board blocking container pieces, transistors FET stripping segment switches and other components. suspects.
, its purpose is to first to ensure that the components measured normal general testing tools can be used (such as multimeter) to solve the problem will not make it complicated.

Principle: after the first outside
if circumstances permit it is best to have a board awaiting repair circuit board as a reference. Then use the double bang VI curve tester scan feature two boards bad comparison test. comparison test starting point from the ports of the circuit board to start; then outside to the inside, especially compared to the capacitor test, which can make up for the multimeter line is difficult to measure the the capacitor leakage defect.

Principle: first, the less difficult
do to improve test results before the circuit and functional testing of the circuit board to deal with the repair plate some technical handling the impact of the testing process to try to weaken the various interference The specific measures are as follows: the
1. the preparation before
under test crystal short circuit (attention to the four-legged crystal must understand that his legs for signal output pin can be shorted feet. remember the other two general feet for the supply pin must not be shorted) but also for the large-capacity electrolytic capacitor welding under kick it open will also have a large-capacity capacitor charging and discharging the same interference.
2. process of elimination any testing (or more normal) devices directly to confirm the test results give a record not pass the test (or more ultra-poor) can test the device online test or comparison test process test
the device again or not confirm the test results. been testing go on until the finished device test board (or comparative). then deal with those who did not pass the test device (or comparison-tolerance).
not a function online devices tested some test instrument also provides a less formal but a more practical approach: Since the test instrument can also be powered on the circuit board through the test clip applied to the device corresponding to the power supply and ground line feet implementation of blade cutting device power pin this device from the power supply system board.
time you line functional testing of the device; electricity will not work due to other devices in the circuit board eliminate interference. actual test results will be the same as "quasi-offline test measurement precision is greatly improved.