LN52C530 sound, picture, no backlights/volts from power supply

[DXseekerMO]

So this Samsung LN52C530 comes to me from the free pile. I figure these will be good to learn on and maybe help offset the cost on ones I mess up.

Has sound, confirmed picture but no backlights and no power from the plug that goes over to the backlight inverter board.

What I'm hoping to find is a flow chart/repair guide for the power board and give this a go solo, just haven't found anything and hoped someone could point me towards one?

If there's any checks I can do that anyone knows of that would be great too.

Thanks

[budm]

Re: LN52C530 sound, picture, no backlights/volts from power supply

You have power supply/inver board combo, the long green board connected to the lamp is the balance board.
You need to report the DC V reading of each pin of the connector CN802 that goes to the main board when TV is OFF and when the power switch is activated.
You MUST, repeat, MUST pin down the pin name and follow by the Voltage readings.
I.E.
Pin 1 B13V = ???VDC when TV off, ??VDC when power switch is activated.
Do them in that format so we can easily see what we have or do not have.
The exposed pins you can see from the top side of the board are ODD number pins.
We also need the DCV of connector CNI802.
What ever you do, do not try to measure the high Voltage connector going out of the power supply/inverter board unless you want to damage your meter.
BTW, this power supply/inverter board BN44-00343B is known for having problem with low PFC Voltage that will cause the backlights to flicker.

[DXseekerMO]

Re: LN52C530 sound, picture, no backlights/volts from power supply

OK cool, I will do that tomorrow.

The report on this one was "all of a sudden....picture went dead"

Thanks!

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

n/a

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

https://elektrotanya.com/ Service manual.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

https://elektrotanya.com/?q=showresult Looks like the 5th one down.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

https://www.badcaps.net/forum/showth...89985&posted=1
This thread may be relevant if you have low PFC voltage, check voltage on CP802 and CP803 CAREFUL HIGH VOLTAGE DEADLY SIDE, should be around 160 with tv plugged in and turned off and around 380 with tv powered on.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

https://www.badcaps.net/forum/showth...89985&posted=1
This thread may be relevant if you have low PFC voltage, check voltage on CP802 and CP803 CAREFUL HIGH VOLTAGE DEADLY SIDE, should be around 160 with tv plugged in and turned off and around 380 with tv powered on.

Your problem may be different tho, their symptom was flickering.

[DXseekerMO]

Re: LN52C530 sound, picture, no backlights/volts from power supply

You have power supply/inver board combo, the long green board connected to the lamp is the balance board.
You need to report the DC V reading of each pin of the connector CN802 that goes to the main board when TV is OFF and when the power switch is activated.
You MUST, repeat, MUST pin down the pin name and follow by the Voltage readings.
I.E.
Pin 1 B13V = ???VDC when TV off, ??VDC when power switch is activated.
Do them in that format so we can easily see what we have or do not have.
The exposed pins you can see from the top side of the board are ODD number pins.
We also need the DCV of connector CNI802.
What ever you do, do not try to measure the high Voltage connector going out of the power supply/inverter board unless you want to damage your meter.
BTW, this power supply/inverter board BN44-00343B is known for having problem with low PFC Voltage that will cause the backlights to flicker.

Ok here's what I have: (s = steady voltage reading)

PIN VDCoff VDCon

CN802:
1: 0 12.46s
2: 0 0
3: 0 12.46s
4: 0 5.14s
5: 0 12.46s
6: 0 1.65s
7: 0 0
8: 0 1.82s
9: 0 0
10: 0 0
11: 0 5.15s
12: 0 0
13: 0 5.15s
14: 0 5.15s
15: 0 12.45s
16: 5.15s 5.15s
17: 0 12.45s
18: 0 .87s

CNI802 (checked w/TV on)

1: 12.36s
2: 0
3: 0
4: 0
5: 0
6: 9.1s
7: 9.1s

CP802: 166s 390
CP803: 166s 390-391

https://elektrotanya.com/ Service manual.

https://elektrotanya.com/?q=showresult Looks like the 5th one down.

https://www.badcaps.net/forum/showth...89985&posted=1
This thread may be relevant if you have low PFC voltage, check voltage on CP802 and CP803 CAREFUL HIGH VOLTAGE DEADLY SIDE, should be around 160 with tv plugged in and turned off and around 380 with tv powered on.

Your problem may be different tho, their symptom was flickering.

Thanks! Got the manual downloaded! I appreciate it!

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

Check this video, about 16 minutes in. he's testing backlights by grounding the test pad, I fixed mine by this method, HEED THE 1000 VOLT DEADLY WARNING. if you find one and your backlights stay on then you found a bad backlight or transformer.
https://www.youtube.com/watch?v=Dh01ZepjDp0

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

Could be a problem with powersupplly,
I couldn't understand your voltage readings. The backlight test is pretty easy to do and conclusive.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

CP802: 166s 390
CP803: 166s 390-391 this looks good, you have the voltage required to turn on backlights, I'd do the backlight test in the video.

[DXseekerMO]

Re: LN52C530 sound, picture, no backlights/volts from power supply

I looked at the video and thanks for the link. It looks like his backlights come on then go off. My backlights are completely dead from the minute it comes on. Just wondering if the troubleshooting is the same?

[DXseekerMO]

Re: LN52C530 sound, picture, no backlights/volts from power supply

Could be a problem with powersupplly,
I couldn't understand your voltage readings. The backlight test is pretty easy to do and conclusive.

First set of numbers is from connector CN801, First number is the pin number, second is voltage on that pin TV off and third is voltage on that pin TV on.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

I looked at the video and thanks for the link. It looks like his backlights come on then go off. My backlights are completely dead from the minute it comes on. Just wondering if the troubleshooting is the same?

It's strange, I think his would warm up then shut down, I had same problem he did but mine went out instantly, I would try it, just like he does, see if you get the lights to go on, you dont need to solder on 12 test wires like he did, I think he did that because it took so long to go out he didn't want hold it in place that long.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

I couldn't tell which was the bl_on signal voltage on your readings, if that's good, it usually reads around 3 or 5 volts, then I don't know why the backlights wouldn't come on, unless its a bad ccfl/single backlight or one of those transformers on that balancer board.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

The bl_on signal comes from the mainboard, if you are not getting that the backlight wil not come on, then the problem would be with the mainboard or the connector harness going from mainboard to powersupply.

[nomoresonys]

Re: LN52C530 sound, picture, no backlights/volts from power supply

If you don't have the bl_on voltage present you could try unplug balancer from powersupply board and see if you get the bl_on voltage.

[DXseekerMO]

Re: LN52C530 sound, picture, no backlights/volts from power supply

No volts A/C on all sense lines.

[DXseekerMO]

Re: LN52C530 sound, picture, no backlights/volts from power supply

If you don't have the bl_on voltage present you could try unplug balancer from powersupply board and see if you get the bl_on voltage.

Is the balancer connector the wide white one? Don't see a BL_on pinout