Original Bulb Lamp With Housing The original projector bulb lamp with housing is installed with the original brand factory projection lamp, providing bright and clear pictures, visual appreciation, high quality and worry-free service. It can be directly put into the projector, the installation is simple, and no reassembly is required. Original Bulb Lamp With Housing,Buy Projector Lamp,Projector Lamp Light,Original Projector Shenzhen Happybate Trading Co.,LTD , https://www.happybateprojectors.com
The following causes are generally caused by the fact that the LCD TV cannot be turned on:
1. The power cord is not connected or the power adapter has no voltage output.
2. There is no voltage output of the switching transformer inside the TV, and the surrounding electronic components are abnormal.
3. The power board is abnormal or the switching power supply module (IC) is abnormal.
4. The remote control has no electricity or is damaged.
5. The TV control panel has broken or leaky keys.
6. The motherboard and CPU circuit are abnormal.
7. There is a short circuit in the high voltage board, Y board, and buffer board.
Skyworth TV: 
Symptoms: No boot, no picture, silent, black screen and other faults.
Analysis and processing:
A. The indicator light is bright but unstable, indicating that the 5V standby voltage is abnormal, the 5V voltage measured by the meter is only about 3V, and unstable. Then start checking the IC12's peripheral and feedback voltage stabilizing circuit. No abnormality is found after inspection. Then substitute IC12, the fault remains unchanged, the standby circuit outputs a total of 2 groups of voltages. One group is 5V. One group is 30V. Then the 30V output is disconnected. 5V is returned to normal. That means 30V. There is a problem. The measured D30 has been soft-flopped. Wear, replace LCD TV troubleshooting.
B. After the power on, it is found that the indicator light is off. It is suspected that the problem is in the standby circuit or the front stage. Measuring the voltage of the 300V capacitor is only about 300V, indicating that the PFC circuit does not work. The power supply for the standby circuit is also measured. There is no power supply output for 5V and PFC. The problem should be in the standby circuit. The voltage of the standby IC is also not abnormal. Substituting the IC is also not good. There is no problem in measuring R96 and Q13. Later, it was not intended that D23 found that it had been broken down, and that the replacement LCD TV had resumed normal work.
C. Open the cover and find out that the power supply fuse is burned. D1 IN5406 and Q7 K2837 of the PFC circuit are further detected. Under normal circumstances, the replacement of the above components can be repaired, but sometimes the above components will be bad and the bad bridges of successive rectifier bridges will continue generations of Z6. The 180V regulator tube is bad. If there is no 180V regulator tube under emergency conditions, the Q6 wire can be directly connected to the Q6 Q6 wire and the LCD TV can resume normal operation. 
Symptoms: The phenomenon of auto-stepping occurs from time to time after turning on the TV. There is a sound.
Analysis and processing:
a. Check the control panel for leakage.
b. Check the panel key switch for leakage.
c. Check the remote receiver for leakage.
d. Check the CPU related circuit for leakage.
e. Check if the voltage of each pin of the tuner is normal.
f. Replace the high frequency head directly.
Skyworth LCD TV can not open the solution:
(I) Check if the power supply of 300V power supply board is normal. If not, check the power supply front-end circuit, such as transformer, voltage regulator IC, rectifier diode, and filter capacitor.
(2) If there is 300V power supply, please check whether the power supply board 5V, 24V, 12V has power supply; please do not check the small resistance, capacitance, etc. around the switch power supply. If yes, please check the motherboard, CPU circuit, etc. 
Skyworth TV repair point experience summary:
The phenomenon of auto-stage jumping on the TV is that you can unplug the control panel cables and continue testing. If you do not jump again, it means that the panel is leaking. Please clean the panel, replace all the buttons and try again. If the fault persists, check the relevant resistance and capacitance of the key drive circuit on the main board. If no abnormality is found, replace the high-frequency head and retry the test machine.
Sharp TV: 
Symptom: Randomly fails to boot normally.
Analysis and processing:
Can not boot normally first suspect that the switching power supply circuit and remote control system control to open. Shut down the corresponding circuit. Therefore, when the fault occurs, check that the power supply pin 52 of the microprocessor N701 (M50436-560SP) has a normal +5.0V, and press the standby button on the remote control, the voltage on the remote control signal input pin 5 of the N701 fluctuates, indicating that There is a remote control signal input to the microprocessor, but its power on/off pin 9 does not have any signal output, check the reset pin 27, the voltage is only +4.1V, deviate from the normal value, check the standby power circuit and start the circuit, test The voltage on the C834 is only +5.6V (normally around +1OV).
Check the capacitor C834, found that its leakage, capacity reduction, so that the standby power supply voltage is too low, the microprocessor's startup circuit V810 can not provide a normal reset voltage to the N701 pin 27, so that the microprocessor does not work, causing the aforementioned fault Phenomenon, replace a new component of the same type, power test, the TV troubleshooting.
Symptom: A random automatic shutdown has occurred.
Analysis and processing:
The failure phenomenon indicates that the color television switching power supply circuit or the power supply control circuit has a problem. Therefore, it is checked that the switching power supply output DC voltage is +110V and +18V, and then the pin of the microprocessor N001 (TMP47C433AN-3849) of the remote control system is checked. 42 Power supply terminal +5.0V, normal. When checking the pins 31, 32 of the N001, the TV returns to normal.
When the G001 (4MHz) crystal is toggled, the fault reappears. After careful observation, one foot of G001 is soldered to the circuit board. After re-welding, the power test, the color TV troubleshooting. It turned out that the poor contact of the crystal caused the remote control system to be abnormal and the above fault phenomenon occurred. 
Symptoms: Occasionally working, sometimes unable to boot or automatically shut down.
Analysis and processing:
Through analysis of the switching power supply of the machine, it is considered that most of the faults are switching power supply, line scan circuit abnormality or overload, protection circuit action or remote control on/off control circuit is faulty, and the microprocessor abnormality sometimes cannot output the startup command or Its command signal is lost midway, etc.
Power on and measure the power output + 115V, +24.5 V voltage is normal, when the fault occurs, then measure +1 15V, 24.5 V output voltage, respectively 65V and 15V. Description The power supply is in standby.
Measure the @ foot of the microprocessor (TMP47c1638Au353) to be 5v high. Pressing the On/Standby button does not change this level, so the microprocessor has a problem. First of all, check the @V power supply terminal voltage is 5V. Check the relevant components of its periphery, and found that the contact between one foot of the crystal ZA09 and the circuit board was poor, and the fault disappeared after renewed soldering. The microprocessor malfunctioned due to poor soldering contact of one foot of ZA09, resulting in the above failure.
Symptom: Automatic shutdown occurs without regularity, but the power indicator does not change.
Analysis and processing:
According to the phenomenon of "failure in automatic shutdown," it can be initially determined that there is poor thermal stability of the components in the circuit, or the phenomenon of poor soldering or poor contact; while the power indicator can still be weak and does not change during shutdown, the faulty component can be judged. Certainly in the line scan or line output circuit.
When the automatic shutdown fault occurs, observe that the display tube filament does not emit light, and accordingly confirm that the line scanning circuit is operating abnormally. At this time, the voltage at the power terminal of the N2010 foot scan circuit is detected to be 11.9V, normal, and then the voltage at the 27-pin of the excitation output terminal N201 is detected to be 0.6V. At this time, the output signal waveform of the 38th foot of the N201 is detected to be 1.4VP- P line excitation positive pulse signal output, thus indicating that the line oscillation and N201 in-line excitation circuit works normally.
The voltages at the base and collector of the drive line are respectively detected to be 0.5V and 0V. Obviously, the V430 has no collector power supply. At this time, the power is cut off and the V430, C429, and C430 components are tested for no short-circuit damage, and then used. The magnifier carefully observes the push of the transformer T450 primary coil pin and the R432 pin solder joint. It is found that there is a crack in the pin of the R432 and there is a crack in the pin, and the black solder joint is similar to the ignition. Therefore, the R432 pin is removed. Black spots, and re-treatment on the tin, install the original location and re-weld, try it on. The whole work returned to normal and worked continuously for nearly 2 hours. No automatic shutdown fault occurred again. At this point, the fault is eliminated. 
Symptoms: Immediately after power on, there is a "click" sound and there is no light and silence.
Analysis and processing:
According to the analysis of fault phenomena, the power supply section and the output stage section should be checked. Test the power switch transformer T803 secondary output voltage 130V, 24V, 25V are zero, disconnect R411 (5.6Ω/3w) after welding between the 130V output L806 and the ground welding 220V/100w bulb as a false load, start the test Several sets of output voltages are still zero, indicating that the fault is in the power supply section. Due to the fact that the power supply has started up immediately after starting the power supply, it is suspected that the protection circuit has been operated.
Check the thyristor V819 protection circuit components. It was found that the voltage regulator diode V820 (6.2 V) on the V819 (SFORIlM2) G pin has broken down. After switching on, the output voltages of 130V, 24V and 25V are all restored to normal. Remove the dummy load and weld the R411 tester. Both the image and sound are normal.
Symptom: The indicator light is on, but the power supply cannot be turned on and it is not light or silent.
Analysis and processing:
Because it is "three nos", the output voltage of each group is first tested to be normal, indicating that the fault is in the load circuit. The 30-pin (power control terminal) of the CPU (IC1101) is 0.3V and the Q1110 is off, indicating that the "three-nothing" fault has nothing to do with the power control circuit.
Because the machine can start and row scan circuit work or not, so in the IC501 (HA51339SP-3) 7 feet and ground welding two wires connected to the multimeter 50V block, observe the momentary moment of the start of the 7-pulse fluctuations, after boot No reaction. Further measured IC501 8 and 9 pin voltage is about 2.2V (normal is 7.7 V), determine the fault in the IC501 and its peripheral circuits. Check the IC5017, 8 and 9-pin external components, and replace the current C707 (2200pF) capacitor tester.
Samsung TV: 
Symptoms: No boot, no next boot analysis and maintenance:
The voltage of pin 4 of microprocessor N801 (LC8645J6V -5C18) is detected to be 0.6V. Indicates that the aircraft is in standby protection. The N801's 41-pin external jumper W071 is disconnected. The protection circuit is about to be disconnected. The power-on raster is normal, but the image appears as a treadmill, which indicates that the AFT circuit of the aircraft is faulty.
Machine AFT voltage from the N201 (LA7687) 7 feet, after the voltage divider R177.R176, R175 added to the microprocessor N801 13 feet, measuring N201 7 pin voltage is 4.2V, normal, then test the N801 13 feet The voltage is 4.3V, which is too high and it is determined that there is a fault in the AFT circuit. Disconnect the AFT isolation resistor R176, and then test the N801's 13 pin is still 4.3V, indicating that the N801 is damaged. After replacing the N801, the console was normal and the image was normal, but there was no sound. Then check the audio amplifier circuit N001 (TDA7623M) 8-pin 10-pin voltage is 0V, 9-pin power supply voltage is also 0V, indicating the power amplifier block power supply circuit failure.
Check the amplifier block power supply circuit and found that the current-limiting resistor R645 has been opened. The internal pins 8 and 10 of the sound amplifier block N001 break down. After R645 and N001 are replaced, the fault is removed.
Symptoms: Sometimes the boot fails; there is a "click" at the moment of boot.
Analysis and maintenance:
Check that the 36, 37, and 38 pins of the CPU IC101 (CTV2225) on the mainboard are all grounded, but the 36-pin voltage is measured on the road test. Normally, it is 0V, and when it fails, it is 1.5V. Welding 36 feet, boot failure is ruled out, there are pictures and sound. Apply a 680Ω/5W resistor to the 59-pin C337 (1000μF/25V) of the amplifier LA444 to relieve boot-up “clickâ€. 
Symptoms: The image and sound are normal, and there is no blue background when there is no signal.
Analysis and maintenance:
The blue background of the aircraft is controlled by the 25-pin output signal of the microprocessor N906 (WL6805). When there is a signal without a blue background, the 25-pin voltage is 0V; when there is no signal and there is a blue background, the 25-pin voltage is 4V. When pin 25 is high, V909, V910 turn on, make N201 (OM8361) 16 foot voltage is OV, at this moment N201 internal switch chooses blue background signal output, at the same time, V909 sends the blue background signal that follow is sent to by R996 N201's 24 pin (B input), after the internal processing of N201, output the blue background signal from the 18 pin to the blue video input stage to check the N906's 25 feet in the absence of signal voltage is 3.9V, normal, V909 base and emitter voltage They are 3.5V and 3.2V, respectively. The V910 base voltage is 0.7V. Normal, indicating that the blue background control circuit is normal.
Re-test N201's 16-pin voltage is 0.2V, indicating that the N201 internal switch has selected the blue background signal output, but at this time no blue background and screen no light, it is estimated that N201 is damaged, try to replace the OM8361 IC test machine blue background function Back to normal.
Symptoms: Automatic shutdown from time to time, can not be switched on immediately after shutdown, wait a few minutes after the boot can work, the fault repeats.
Analysis and maintenance:
The fault is caused by the poor thermal performance of the zener diode ZD752 of the overvoltage protection circuit and the voltage regulation value is reduced. The controllable Q902 is falsely triggered to turn on, causing the 111V voltage to be short-circuited and the switching power supply to stop vibration.
(1) Monitor the thyristor Q902's gate voltage to determine whether the protection circuit is operating. The G-pole voltage monitored by Q902 is about 0.7V, indicating that the protection circuit has operated.
(2) Determine which protection circuit is operating by measuring the voltage at characteristic points such as C751, R781, and Q721 c-poles. According to the circuit analysis, when the voltage on C751 exceeds 19V, the overvoltage protection circuit operates; when the voltage across R781 exceeds 5V, the overcurrent protection circuit operates; when the voltage on c721 of Q721 exceeds 35V, the shutdown protection is performed.
The voltage across the over-current protection sampling resistor R781 and the c-pole voltage of the line stop protection characteristic point Q721 have been found to be normal, indicating that the fault is not caused by over-current or line stop protection. Detection C751 voltage is lower than 19V, but the ZD752 (HZ22L2) positive terminal voltage becomes 7V in the automatic shutdown (normal voltage regulation value is about 20V), indicating the overvoltage protection circuit ZD752 stable diode performance is poor, after the replacement failure exclude. 
The fault is as follows: The horn has a karaoke sound, and the image is clearly flashing, and a white horizontal bright line appears intermittently.
Analysis and maintenance:
From the fault perspective, the public channel circuit has poor internal contact with the components, causing the TV to ignite, the image flickering, the whispering lines on the screen, and the rattle in the speaker. As it is difficult to determine the location of such failures, it is not easy to determine and determine the major parts of failures, unlike those that are obvious and fixed.
These circuits include the integrated amplifier circuit and the public circuit in front of it, namely, the integrated circuit itself, SAW filter, image IF preamplifier, high-amplitude automatic gain control circuit, and high-frequency amplifier circuit. When checking the circuit, if there is an oscilloscope, the waveform test method can be used to narrow the fault faster. Without this condition, the large part of the fault can be determined by reducing the parts step by step using the injection signal method.
Repair process:
1. Measure the neutral voltage of the integrated circuit and check the operation of the integrated block.
2. Disconnect the SAW filter and use a 1000 PF capacitor to place the signal in the IC and the fault will disappear. Description There are sparking phenomena inside the SAW filter. If the surface acoustic wave filter is not an internal short circuit, it is impossible to accurately judge the quality of the SAW filter by measuring the resistance. Therefore, it is better to judge the quality of the SAW filter by using the spanning method. The SAW filter was replaced and the TV returned to normal.
Panasonic TV: 
Symptom: TV can not boot, the indicator flashes, the key does not work
Analysis and maintenance:
The measured +B output voltage is 30V, and the +5V output voltage swings around 4.2V. It is apparent that the microprocessor does not work and the buttons do not work. The TV is in the standby state.
Turn off the V683 and boot normally. Check the 5V voltage regulator circuit, in turn disconnect the 5V connected circuit, when the disconnection of the reset circuit V824, 5V returned to normal, no problem found in the circuit detection reset circuit components, the reset circuit components re-welding again, the boot moment is normal, try After the V824 is switched on, it indicates that the V824 performance is deteriorated.
Symptom: After the power is turned on, the degaussing relay is repeatedly pulled in and the television cannot start normally.
Analysis and maintenance:
Turn on the power, check the data line (SDA), clock line (SCL), and find that the voltage of SDA is reduced from about 5V to about 2.0V. This TV set was originally repaired because of a failure in the turntable to turn. This was the case after being repaired by the repair department.
Therefore, first check the voltage of each foot of the IC1802 of the K-substrate (turning circuit) and find that there is no +9V voltage at the 16-pin. This +9V voltage is obtained by stepping down +15V from IC1803. Check if there is no +15V on the CN1803. Check the voltage on the CN0531 pin 1 of the D baseboard for no +15V. Check the R625 disconnection and D604 breakdown. After the replacement, the power is normal.
Note: After the power-on relay is turned on repeatedly, the SCL and SDA (clock and data line) voltages should be checked. If it is abnormal, check the location of the fault. This machine is the K board IC1802 after the +9V voltage disappears, causing the 14-pin data line voltage is pulled down, so that the data line voltage is abnormal, causing the boot can not pass data, resulting in failure. 
Symptom: When the power is turned on, it sometimes fails to start. Sometimes, although it can start work, the image of the screen is like a “screenâ€, and sometimes it will automatically shut down.
Analysis and maintenance:
According to the user's introduction, combined with the aircraft circuit structure, the initial judgment may be in the circuit between IC401 (SAA7117A) and IC105 (MST5151A). It should focus on checking this part of the circuit first.
1. Determine the approximate location of the fault
(1) After the power is turned on, the IC401's power supply voltages are quickly measured. No obvious abnormality has been found.
(2) The I2C bus voltage of the IC401 is checked, and it is normal. It is checked that the oscillating waveform generated by the oscillating crystal in the clock oscillation circuit is normal. At this point, it is suspected that the IC401 itself is not good.
2. Troubleshooting
IC401 integrated circuit model SAA7117A, with a model of integrated circuit replaced, troubleshooting.
In many cases, we have encountered a TV that cannot boot normally, but we do not know why the TV cannot be switched on. What should we do if something goes wrong? Today, we will discuss together.