TCL L46P10FBEG LCD TV after the start-up of the relay does not stop the fault - News - Global IC Trade Starts Here Free Join

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Repair a TCL L46P10FBEG LCD TV. After the fault occurs, the relay will keep moving and the whole machine will not start.
The machine power supply uses the FSQ510 power module to provide 3.3V standby power to the motherboard. After the power is turned on, the 3.3V power supply output is low, and the P-ON signal outputted by the motherboard is constantly changing with the value of the relay pickup. At this point, the power board suddenly jumped three times, and the whole machine was out of power!
Quickly look at the location of the flashover and supply a corner of the filter capacitor for the standby power supply. Under welding, it was found that the capacitor was moldy and the measurement capacity was gone. Replace the 4.7uf.450V capacitor with the same specification. Check the FSQ510 three power supply current limiting resistors to burn, it is estimated that this power chip can not be spared, and replaced together. At this time, the power is turned on, the voltage of 3.3V is more than 2V, and the frequency of relay pickup is faster!
Check the power block and find that the feedback angle is shorted to the ground, replace it with a new one, and start the TV to start normally. The long-lost startup screen and sound are exceptionally beautiful.
Summarize this maintenance, this is 4.7U filter capacitor loss of capacity, the 3.3V standby power supply provided by the motherboard causes the relay to intermittently pull. The capacitor is slightly moldy and weak, which causes the flashover to damage the standby power module and the current limiting resistor.