So I got this tv for free and I'm stubborn. I know this led power supply is my problem, it has 320DC volts in (that's the right amount) and literally none out anywhere. I replaced 4 of the capacitors that were bulging. Still no power out. So I'm trying to figure this out. On the back of the board one part looked pretty bad. So I tested the diode with the sound test on the multimeter. It beeped. No other diodes on this board did. So I pulled it tested it out of the circuit well it works. No beep. So I tested the board it beeps. Below are some images if anyone needs different shots or numbers for something I'm willing to. Any help would be highly appreciated this board costs $75 and I just don't feel like spending that

 

The circuit is a smps chopper using a LNK304pn chip, have a look at the datasheet for this chip and compare it to your circuit.

Ideally you need to get the service manual for the TV model.
Here is an example of a circuit for this chip...

 

Okay I have work in a few but I will find a manual for it. Thank you

 

So the manual I find doesn't give me the sub power supply diagram. samsung hl67a750a1fxza if anybody is able to find it that's the model of the tv.

 

So I got this tv for free and I'm stubborn. I know this led power supply is my problem, it has 320DC volts in (that's the right amount) and literally none out anywhere. I replaced 4 of the capacitors that were bulging. Still no power out. So I'm trying to figure this out. On the back of the board one part looked pretty bad. So I tested the diode with the sound test on the multimeter. It beeped. No other diodes on this board did. So I pulled it tested it out of the circuit well it works. No beep. So I tested the board it beeps. Below are some images if anyone needs different shots or numbers for something I'm willing to. Any help would be highly appreciated this board costs $75 and I just don't feel like spending thatView attachment 144179 View attachment 144179 View attachment 144179 View attachment 144180 View attachment 144179

It’s seems like this diode is Run DC Diode. But it’s not shorted so you must check the supply line for power IC or remove ic from board and test its Vcc and ground pins with multimeter diode function for any similar values in both directions of probing. If you find two readings that your IC has shorted and you must change with new. Also check your chopper transformer primary and secondary windings with ring tester. Check e-caps for short or leaky and check other components along with your diode which you had removed from board.

 

So the manual I find doesn't give me the sub power supply diagram. samsung hl67a750a1fxza if anybody is able to find it that's the model of the tv.

The 320 volts that you do get is the rectified AC mains voltage at the input of the supply. All of the other parts are part of the actual switching system, which is not working, since you get no output. My guess is that small IC device, but first check that the values of the other parts, resistors and capacitors, and check the inductors for continuity. The one diode is a fast schotkey type, or similar, you will need a data sheet to know the correct forward voltage drop. But also consider that small 12 volt DC supplies are very common and fairly cheap, and so adding a separate supply might make sense for a free TV. But you can also try substituting a different source of 12 volts and see if everything else is working, so that you will know if the set is worth fixing, or is it just good for parts.