Chigo CS-25V3A-MA114A, Руководство по обслуживанию

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(1) SCR: measure resistance between control electrode and positive electrode by multimeter, model Z47 is
20Ω to 400Ω, BT131 is 1.4K ~ 1.7K, if the resistance is too large or too small, means not normal. And if
the resistance between other electrode is infinite,means SCR damaged.
(2) Check the voltage between input terminal and output terminal.if input voltage is ok and did not have the
output voltage,need to replace the relay.
(3) Optocoupler: the red pen connect the first leg of optocoupler, black pen connect the second leg.if the
forward Resistance is about 1K,and the resistance between other feet is infinite, means optocoupler
damaged.
(4) transformer: primary coil resistance is 400Ω
～
1000Ω, Secondary coil resistance is 15Ω
～
40Ω,transformer damaged if deviation is big.
(5) Temperature protective tube, varistor: resistance of protective tube should be 0Ω, that is, resistance of
varistor should be infinite.
(6) Main Chip: check the working voltage (5V) and voltage of reset feet and crystal oscillator, and then check
peripheral components Step by step.
(7) 2003(IC): 2003 is an inverter, in the working condition, input and output potentials are always contrary,.
(8) Diodes: choose “diode” from multimeter, then the red pen connect positive pole, black pen connect
negative pole, the resistance should be a few hundred ohm.the reverse resistance is infinity, otherwise
diode is bad.
(9):Transistor:
①
: NPN transistor: choose “diode” from multimeter,red pen connect base
、
black pen connect other two
feet. and the resistance should be a few hundred ohm, otherwise the transistor damaged.
②
: PNP transistor: choose “diode” from multimeter,black pen connect base
、
red pen connect other two
feet. and the resistance should be a few hundred ohm, otherwise the transistor damaged.
(10) Infrared Receiver Module: choose “diode” from multimeter,black pen connect power pin
、
red pen
connect other two feet. and the resistance should be a few hundred ohm, otherwise the transistor
damaged.
(11) Crystals: check voltage of crystals.the normal voltage is 2.1 V - 2.5 V,otherwise the crystals damaged.
2
）、
Charged detection:
(1) Connect PCB with Test-bed.check mode
、
wind speed
、
temperature and so on according to the remote
control and control panel. PCB should receive signal accurately and correctly, and indicator light should
feedback correctly or check whether has the correct output signal by a multimeter(such as: compressor
、
fan
、
four-way valve
、
electrical heating
、
step motor
、
synchronous machine
、
negative ion
、
High voltage
generator
、
Dc decelerating motors.)
(2) Each function control key should be flexible,
(3) For liquid crystal display or fluorescence display,character should be clear and correct; There should not
have the ghosting,brightness blance. Light board display normally, have no obvious Unnormal flicker.
(4) step motor should be able to rotate;;
(5) For the PCB with self-test function,press the self-test button, and then enter the self-test program.the
output should be consistent with the design requirements,no procedures chaos or system halted.
3
）、
Common fault detection
(1) unit doesn’t work
a), check whether input and output voltage of the transformer is normal (input AC220V, Output AC10V
~ 14V), if no problem,then check the next step;
b), check whether “three-terminal voltage regulator 7805” is normal, if no problem,then check the next
step;
c), check whether the voltage of crystal oscillator is normal (2.1V-2.5V), if not, replace crystal;