LCD TVs can be said to be a relatively backward electronic device, but this does not affect the fact that LCD TVs are still the main video equipment in many homes. It is precisely because LCD TVs have a very wide audience, so many people have made some conclusions about some of our LCD TVs. Xiao Bian will introduce the maintenance of LCD TVs in the following, and it is also some tips from the great working people. Then, Xiaobian will tell you about it.
Power supply repair is not difficult, the maintenance steps are in mind;
Open the case to view the insurance, severely burned black and urgently change!
Is there a short circuit in the rectification filter? Can the large tube be broken down?
Is the degaussing resistance bad? Check the clearance carefully!
Insurance is in good condition, +B, 300 test,
Filter capacitor If the power is stored, first change the starting resistor;
Pulse width adjustment small electrolysis, the culprit is not ordinary,
In order to be safe, I decided to change all of them.
After measuring the primary secondary view: the load short circuit is not normal,
Regulator protection and behavior, line reversal and deflection,
Protecting the circuit is the key, and it is dangerous to disconnect at will;
If it is not easy to find? Try to change the module,
Power failure is accurate!
Line scan section:
Line sweeping faults are the most frequent. Repeated burning tubes are the most annoying. Is it correct to measure positive B first?
Careful inspection of Mo Shiyan, the rise of the tube is dangerous,
Line-changing short-circuit is the most common, and the reverse-capacitance and deflection, and short-circuit should be clearly identified!
Insufficient push to check, does the resistance capacity change?
The oscillation frequency is the key point, and the crystal oscillator is best changed directly;
The pillow is more faulty than the circuit, and the deflection cannot be broken freely!
The last sentence is forgotten, and I can't afford to check the power supply.
Field scan section:
Field sweep circuit failure frequency, horizontal bright line is the most annoying,
The upper and lower curling interference lines are more worrying.
The heart of this failure is awkward, and the field electrolysis is completely replaced!
Maintenance switch, don't neglect, sometimes can fool people;
The linear amplitude is small, and it is a curse.
If the field can't be shaken, it's a big trick.
The power supply of the field block has positive and negative, and the hard work pays off!
Public channel section:
There is no picture and no sound, turn off the blue screen and see clearly.
The surface of the sound surface is betrayed, and the front and rear faults are the most distinct;
Can the tuning voltage change? Is the conversion voltage flexible?
Focus on checking the AGC, no image can not be repaired;
The last generation of high-frequency heads, carefully check the affirmation!
The image running platform is the most common, does the tuning voltage change?
Has the exchange been changed in the middle of the week? Does the AGC voltage look?
Check the quasi-feeling carefully. The sound is dull and silent.
First look at the speaker, the sound filter,
The 500 crystal oscillator is not relaxed, and the power supply of the power amplifier should be checked first.
The system conversion should be clearly recorded, and the quasi-successful inspection should be carried out carefully, and the sound should be loud as a bronze bell.