Hello
I have a led tv samsung UE32C5100.
After repairing at the primary section of the power supply BN44-00351b which a diode and the mosfet are faulty . The tv refurbished a day.
Then the second day I tried to start the TV after several attempts (unplug reconnect ac cable) she started once or twice. Then nothing else she does not want to start any more. Some day the tv work correcty some day the tv can't power on. It's random
When don't power , After checking the voltages of the cards, I noticed when we try to turn the tv that the voltage of the primary PFC goes up to 380V and then drops back to 340V. once dropped back to 380v. It makes these cycle rise descent in permance.
When it reaches 380V we hear a whistle sound at the coil next to the backlight connector. The backlight voltage goes up to 99V when the PFC voltage is 380v then drops back to 52v when PFC is 340V.
The 5v STB voltage is always present. The 12v voltage goes from 15.3v to 12.6v when PFC respectively from 340v to 380V
The voltage 5.3v goes from 0v to 5.2v when PFC respectively from 340v to 380V
I tried to disconnected the connector of the mainboard and I shunt the PWON to 5VSTB the backlight is on and the voltages are OK, we find (5v, 5VSTB, 12v, 198V)
According to the info on the power supply board, the voltage D5.3V - 2.3A, D12V - 1.4A and the backlight voltage 188.5v - 0.24A. I think that when the motherboard is connected to the power supply, the motherboard tries to pump more energy on the capacitor of the primary because the voltages D12v and D5.3v pump a lot of ampere, that's why the PFC voltage drops from 380V to 320V which prevents the TV from power on.
Are the capacitors of primary faulty? What do you think of my interpretation otherwise would you have another idea?
thx
I have a led tv samsung UE32C5100.
After repairing at the primary section of the power supply BN44-00351b which a diode and the mosfet are faulty . The tv refurbished a day.
Then the second day I tried to start the TV after several attempts (unplug reconnect ac cable) she started once or twice. Then nothing else she does not want to start any more. Some day the tv work correcty some day the tv can't power on. It's random
When don't power , After checking the voltages of the cards, I noticed when we try to turn the tv that the voltage of the primary PFC goes up to 380V and then drops back to 340V. once dropped back to 380v. It makes these cycle rise descent in permance.
When it reaches 380V we hear a whistle sound at the coil next to the backlight connector. The backlight voltage goes up to 99V when the PFC voltage is 380v then drops back to 52v when PFC is 340V.
The 5v STB voltage is always present. The 12v voltage goes from 15.3v to 12.6v when PFC respectively from 340v to 380V
The voltage 5.3v goes from 0v to 5.2v when PFC respectively from 340v to 380V
I tried to disconnected the connector of the mainboard and I shunt the PWON to 5VSTB the backlight is on and the voltages are OK, we find (5v, 5VSTB, 12v, 198V)
According to the info on the power supply board, the voltage D5.3V - 2.3A, D12V - 1.4A and the backlight voltage 188.5v - 0.24A. I think that when the motherboard is connected to the power supply, the motherboard tries to pump more energy on the capacitor of the primary because the voltages D12v and D5.3v pump a lot of ampere, that's why the PFC voltage drops from 380V to 320V which prevents the TV from power on.
Are the capacitors of primary faulty? What do you think of my interpretation otherwise would you have another idea?
thx
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