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

**nomoresonys** · 03-13-2018, 08:18 PM

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

http://www.shopjimmy.com/samsung-bn4...wer-supply.htm pic. of board.

**DXseekerMO** · 03-13-2018, 08:43 PM

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

Are we thinking power supply? Any component level repairs I can do?

**nomoresonys** · 03-13-2018, 09:17 PM

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

Not sure if this board has pull up resistors, did you try unplug tv from wall or power strip, unplug connector from powersupply board and mainboard, plug tv power cord back in, turn on tv see if backlights come on.

**nomoresonys** · 03-13-2018, 09:20 PM

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

Originally posted by DXseekerMO

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

Hard to tell without pictures.

**nomoresonys** · 03-13-2018, 09:33 PM

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

n/a

**DXseekerMO** · 03-13-2018, 09:43 PM

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

Originally posted by nomoresonys

Not sure if this board has pull up resistors, did you try unplug tv from wall or power strip, unplug connector from powersupply board and mainboard, plug tv power cord back in, turn on tv see if backlights come on.

Do you mean from main to the t-con? I'll lose standby if I unplug the power to main board connector and have nothing?

**nomoresonys** · 03-13-2018, 09:47 PM

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

https://www.youtube.com/watch?v=Z1DEkSguWtg Explaining how the boards signal each other etc.

**nomoresonys** · 03-13-2018, 09:50 PM

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

Originally posted by DXseekerMO

Do you mean from main to the t-con? I'll lose standby if I unplug the power to main board connector and have nothing?

Yes powersupply to mainboard NOT tcon, if it has pullup resistors you will get thebacklight on, did you try it?

**nomoresonys** · 03-13-2018, 09:52 PM

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

If it has no pullup resistors theres a jumper you can do with the powersupply to force on the backlights but I don't know how to do it with this powersupply.

**nomoresonys** · 03-13-2018, 09:53 PM

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

Can you upload the manual here?

**budm** · 03-13-2018, 10:05 PM

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

OK, you do have BL-ON and Dim control signals, too bad you did not put down the pin names for me so I can easily see what are correct or not correct, I had to look at the picture and look at your readings for each pin.
Since the backlights did not even come on for seconds then you need to verify that the fuse FS802S is good or not, that fuse is for supplying the 380V DC to run the backlights circuit, second component to you need to look really close is the cap CI818 (it has 2W 474K printed on top), that cap is the commonly failed cap, it is the coupling /dc blacker cap for driving the primary side of the two inverer transformers. Look really close to see if it has bulging on the side of the cap or not, it is 0.47uF Polypropylene type cap.

**nomoresonys** · 03-13-2018, 10:28 PM

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

CP802: 166s 390
CP803: 166s 390-391 this voltage is present. post 9.

**DXseekerMO** · 03-13-2018, 10:41 PM

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

Originally posted by budm

OK, you do have BL-ON and Dim control signals, too bad you did not put down the pin names for me so I can easily see what are correct or not correct, I had to look at the picture and look at your readings for each pin.
Since the backlights did not even come on for seconds then you need to verify that the fuse FS802S is good or not, that fuse is for supplying the 380V DC to run the backlights circuit, second component to you need to look really close is the cap CI818 (it has 2W 474K printed on top), that cap is the commonly failed cap, it is the coupling /dc blacker cap for driving the primary side of the two inverer transformers. Look really close to see if it has bulging on the side of the cap or not, it is 0.47uF Polypropylene type cap.

budm, I'm sorry about the mix-up. I thought you wanted pin numbers and not pinout description on each. Sorry to make you go through all of that.

Is this the bulge to which you were referring. I tried to take a good picture for posterity's sake.

Attached Files

**budm** · 03-13-2018, 11:05 PM

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

I cannot really tell from the picture, you need to get closer. This bad cap will be bulging from the side and if you check the capacitance it will be a lot less than 0.47uF.

**budm** · 03-13-2018, 11:08 PM

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

Originally posted by nomoresonys

CP802: 166s 390
CP803: 166s 390-391 this voltage is present. post 9.

The 380V DC is fed to one side of the fuse which is connected to the positive leg of the main filter cap, then the other end of the fuse is feed to the inverter circuits only. OP did not indicate that he checks that fuse or not it needs to be verified, unless I miss that info.

**DXseekerMO** · 03-13-2018, 11:14 PM

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

Originally posted by budm

The 380V DC is fed to one side of the fuse which is connected to the positive leg of the main filter cap, then the other end of the fuse is feed to the inverter circuits only.

Try this picture. Bulge circled in gray.

Attached Files

**DXseekerMO** · 03-13-2018, 11:16 PM

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

So if there's no or not enough volts out of that cap then it's bad. Does this correspond to any of the voltage readings I was seeing?

**budm** · 03-13-2018, 11:18 PM

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

You have bad cap.
Do you have cap meter to read its capacitance to see what it shows?
See this thread for the same power supply/inverter board as yours and where to get the replacement cap.
https://www.badcaps.net/forum/showth...ht=BN44-00343B

**DXseekerMO** · 03-13-2018, 11:31 PM

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

I have a DVOM that looks like it has that ability, has an F scale with the micro and nano symbol. 20u and 2u scales.

**budm** · 03-13-2018, 11:33 PM

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

Remove the cap and test it on 2u scale to see what you get, you cannot test it while it is in the circuit.
Do not touch the probe tips with your finger while testing it.

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

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