Samsung LN-T665F

[heavymachines]

Re: Samsung LN-T665F

You need the 5.4V to supply power to the relay coil and when PSON is connected to STBY (5.2V) it should bring the relay on.

You would think but i am about to try again here in few mins.

[heavymachines]

Re: Samsung LN-T665F

With only 75 Ohms resistor, it should be a lot more than 2.7V.

With 75 ohm resistor from pin3 stby5.17v
it reads 4.80v volts on ps_on pin 1 and does not latch!!! I am not kidding.

[heavymachines]

Re: Samsung LN-T665F

Yay figured it out this is what i had to do. i used three 75 ohm resistors to make it work.


first resistor is to be ran from standby to ps_on

the second resistor is to be ran from ground to standby and voila it turns on and all voltages comes up and stable.



i ran another resistor 3rd one on cni-805 Det_5v jumpted to inv-ON/OFF and we have backlights!!!!


Woot so we're good now so clearly the problem is in the main. any ideas where to check there i will start probing around.


So in total you need 3 resistors to force on this TV.

[heavymachines]

Re: Samsung LN-T665F

So if i may folks pick your brains. What could be causing the ps_on to be unstable?


1. Thinking caps is one possibility.

2. Bad regulator.

3. Don't think it would be processor or any of the Bga.

4. Not sure what else lol.

[dskall]

Re: Samsung LN-T665F

Try unplugging lvds, wifi see if that does any good. So when you force it on you have stable voltages? From the main are they stable just cycling?

[budm]

Re: Samsung LN-T665F

'i ran another resistor 3rd one on cni-805 Det_5v jumpted to inv-ON/OFF and we have backlights!!!!' This one does not make sense because DET_5V is the error signal to tell the main board if inverter, backlights are working or not.

[heavymachines]

Re: Samsung LN-T665F

'i ran another resistor 3rd one on cni-805 Det_5v jumpted to inv-ON/OFF and we have backlights!!!!' This one does not make sense because DET_5V is the error signal to tell the main board if inverter, backlights are working or not.

isn't it technically overriding? it did work. If there is an error or something bad on inverter it wouldn't go right? or is it possibly forcing on bad cfl bulbs? if so i should probably watch it longer see if its flickers or pink. I don't know.


It did output touch over 5 volts at Det_5v if that means anything. just borrowed it's voltages to inv_on/off.

[heavymachines]

Re: Samsung LN-T665F

Try unplugging lvds, wifi see if that does any good. So when you force it on you have stable voltages? From the main are they stable just cycling?

I have stable voltages at all connectors at power supply when forced. all within reason no jumps that i seen but for extra measure i will double check in longer time span.

[budm]

Re: Samsung LN-T665F

You should be able to use resistor between INV ON/OFF and the standby Voltage to turn the inverter on.

[heavymachines]

Re: Samsung LN-T665F

You should be able to use resistor between INV ON/OFF and the standby Voltage to turn the inverter on.

Ok that will require a wire as well its got some distance between connectors, i will do this route.


Edit: instead of using wires i'll just jam resistor from it's own wire harness better idea. save from looking for wire.

[budm]

Re: Samsung LN-T665F

At this point I would not worry about forcing on the backlights, it's the main board that you will have to deal with at this point.
You are in the same situation as the other TV with main board problem, if you can hook everything back up except the PS-ON, the Inverter on wires and then just leave the resistors in place. If other functions of the board are OK then you should have image and sound and all other functions.
Same thing as in this thread: https://www.badcaps.net/forum/showthread.php?t=65258