Samsung UE40ES6140 doesn't turn on

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

"I followed the wire PS_ON in the main board and in the end is the wt61p805. The micro controller works fine, if turn on the TV it toggle to 0V and If turn off the TV toggle to 3.3V."
But you have indicated that the PS-ON pin of the main board is connected to the Collector of Q202 via resistor R211 (https://www.badcaps.net/forum/attach...7&d=1571155021), so now you are saying PS-ON is connected directly to the wt61p805 pin?

R211 is connected to the collector and in the other side it go to the power board. Maybe I named bad this signal, but in the text of the main board said PS_ON.
R206 is a pull up with the emitter to 3.3V and other side connected with R222.
R222 is connected to base and R206, to the other side is connected with the micro.
R212 is connected with R211 and collector, other side GND.

Pinout of the transistor like you said in the image.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

Use the diode mode and check that Q202 to see if it is NPN or PNP Transistor.

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

Use the diode mode and check that Q202 to see if it is NPN or PNP Transistor.

I attach the image of the one measure that give the component. Other combinations do not value. The value is 0.320 in diode. I measured it out of the PCB.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

https://www.youtube.com/watch?v=6c31-lwoa3o
http://www.electricalbasicprojects.c...ng-multimeter/
You already know what each pin is.
BTW, 'XFV1' is printed on the Q202?

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

A transistor has two measures, Q202 only has one between pin 2 (black probe) and pin 3 (red probe). Assuming it is a transistor, the measurement is between collector and emitter. The marking on the component is XF1V, I searched the smd book brand without luck.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

OK, it may be MOSFET if you do not get any readings between B and E, B and C.
https://www.badcaps.net/forum/attach...5&d=1571329435
If you reverse the probes on pin 2 and pin 3 do you get any reading?

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

OK, it may be MOSFET if you do not get any readings between B and E, B and C.
https://www.badcaps.net/forum/attach...5&d=1571329435
If you reverse the probes on pin 2 and pin 3 do you get any reading?

No.

I tried to activate the gate to measure between the source and drenator but it doesn't work.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

I have no luck finding the service manual for your TV model, no luck on the XFV1 either.
Based on the diode reading between Source and Drain pin body diode of Q202, it looks to be P-CH.

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

I have no luck finding the service manual for your TV model, no luck on the XFV1 either.
Based on the diode reading between Source and Drain pin body diode of Q202, it looks to be P-CH.

I will try to find a P-CH to replace. It is XF1V not XFV1.

But, if I connect R211 to GND ( without Q202) the power board has to turn On, rigth? Because if I do it, doesn't turn ON.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

I will try to find a P-CH to replace. It is XF1V not XFV1.

But, if I connect R211 to GND ( without Q202) the power board has to turn On, rigth? Because if I do it, doesn't turn ON.

That will ground out the PS-ON Voltage to GND which will keep the power supply board off. The PS-ON pin of the power supply board has pull-up resistor to keep PS-ON pin of the power supply board high when it is not connected to the main board so the power supply will be on, the pull-up resistors on the power supply board are put in place so you can perform power board self test without the need for the main board.

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

That will ground out the PS-ON Voltage to GND which will keep the power supply board off. The PS-ON pin of the power supply board has pull-up resistor to keep PS-ON pin of the power supply board high when it is not connected to the main board so the power supply will be on, the pull-up resistors on the power supply board are put in place so you can perform power board self test without the need for the main board.

Ok, but when turn on the Tv the micro set to 0V the gate of the mosfet, when turn off the micro change to 3,3v. I readed on internet that samsung tv turn on with 0V in Ps_ON. It is why i am confused.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

If the MOSFET is P-CH , then the Gate signal has to be active low for the P-CH turn on (Gate Voltage has to be about 3V leas than the Source pin Voltage).

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

Yes, it is a P-CH. I replace it, and now when turn off the TV in the drenator appear 3.3V. When turn off 2.7V. Now, the A5V not toggle, but is normal because PS_ON always is active to >2V.

[budm]

Re: Samsung UE40ES6140 doesn't turn on

PS-ON Voltage to the PS-ON pin should toggle LOW (<1V) when TV is off to keep the switched power supply section of the power supply board off, it should go HI (>2V) when TV is turned on so it will turn on the switched power supply section of the power supply board on.

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

Finally, I found the problem. It was a capacitor in short circuit in the remote board. I don't know why disconecting the PS_ON the tv works fine.

I attach the image of the board and bad capacitor, for help other people.

Thank you budm for your help and for being patient.

[nomoresonys]

Re: Samsung UE40ES6140 doesn't turn on

Nice fix, how did you figure it out?

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

Nice fix, how did you figure it out?

I found it with lucky, when I was checking the main board I forgot to connect this board and them all voltages were ok. I don't know the features of the capacitor, but I used a bypass capacitor of other board.

[nomoresonys]

Re: Samsung UE40ES6140 doesn't turn on

Ah I see, so this was was dragging down your voltages, thanks for feedback.

[nomoresonys]

Re: Samsung UE40ES6140 doesn't turn on

So was the MOSFET that you replaced also bad?

[raydem]

Re: Samsung UE40ES6140 doesn't turn on

So was the MOSFET that you replaced also bad?

No really, but when I replaced by other P-CH the problem with the voltages didn't appear. But the power supply never turn off. This problems are more difficult without service manual to check it. thank you for your help also.