Samsung UN32N5300 SmarTV -2018

[jason123]

Hi Folks,
Got this TV, with power / main combo board. The TV has the front LED indicator on. Indicator Seems responsive to remote and push button activity.

No Backlight or image with flashlight at all. Optical Audio doesn't come on. First check was backlight. Checks out with tester, but still i opened it up and each LED checks out. 3 strips, 6 LEDs each.

Second check the large cap. It never goes into full voltage (running at 160 VDC), but PFC doesn't seem to kick in. when I press power button, momentarily goes to 163, then back to 160. Any suggestion where to look?

Thanks

[neilc6]

Re: Samsung UN32N5300 SmarTV -2018

Very difficult to debug these combo boards. If TV doesn't turn on, likely issues with the processor or eeprom. I had one with a blown fuse and shorted FET. Replaced both and shorted again. Would just replace the whole board.

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

Check voltages on main. I think optical is on 3.3v

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

3.3 v, 5 v, 12v, 1.9 v are all present. Led voltage is about 27 V differential (not enough to turn leds on- need 54 v or so)

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

Well worst case if rest is working is buy an inverter for your backlights.

[dick_barton]

Re: Samsung UN32N5300 SmarTV -2018

Just a quick thought. Can you check the resistance and inductance of T9101C. There have been a few issues with inductors running hot and failing in the led circuits.

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

Maybe someone smarter than me will jump in. Not sure if there is pfc on this board. Is that one coil for pfc or just filtering?

[dick_barton]

Re: Samsung UN32N5300 SmarTV -2018

Another though is...........have you measured the voltages at the led connector (with leds disconnected) and then power up and see what the voltage peaks to. If ithe peak exceeds the 57V then it's possibly faulty led(s).

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

Just a quick thought. Can you check the resistance and inductance of T9101C. There have been a few issues with inductors running hot and failing in the led circuits.

R = 1.8 Ohm
L= 1.216 mH

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

Another though is...........have you measured the voltages at the led connector (with leds disconnected) and then power up and see what the voltage peaks to. If ithe peak exceeds the 57V then it's possibly faulty led(s).

÷ LEAD READS 110V NEGATIVE LEAD READS 77 V. So Differential is less than 57 v

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

Well worst case if rest is working is buy an inverter for your backlights.

No image is displayed on screen , so not just no backlight, unfortunately

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

Is your processor getting warm? Oscillator working, voltage to eeprom? Thinking you should have a 1.2v to run processor.

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

Is your processor getting warm? Oscillator working, voltage to eeprom? Thinking you should have a 1.2v to run processor.

processor is getting warm, crystal has some activities (loading of a scope pretty much messes it up), and eeprom has 3.3 V. I don't see 1.2 V on the board, but I do see 0.9 (core?), 1.9, 3.3,...

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

Getting voltage to t-con? Data going out on lvds? Voltages on t-con?

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

Getting voltage to t-con? Data going out on lvds? Voltages on t-con?

Getting voltage to TCON - 12V on both sides of the fuse. 3.2V is on TCON also. Initial activity on the LVDS but then nothing

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

And the other t-con voltages?

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

You might want to read some part# off of 8 pin chips around your processor. Maybe multi voltage regulator chips.

[jason123]

Re: Samsung UN32N5300 SmarTV -2018

The only thing that I could find suspicious about the board, is this 630V Cap that is swollen and the epoxy cracked as shown in photos. It's not shorted, and it has about 2.2 nF measured capacitance. Any idea where I can get a replacement if you think it might be the culprit?

I do have a board installed in the TV and it's fine.. Would be nice to fix this one.
Thanks

[R_J]

Re: Samsung UN32N5300 SmarTV -2018

The cap is usually used to connect the transformer winding to ground. digikey should have them

[dskall]

Re: Samsung UN32N5300 SmarTV -2018

Funny it didn't look bulged in first pictures. Now you have a board that you could compare voltages on. Suspect maybe bad processor or firmware.