Samsung 75 LED UN75F6300

[Gv137a]

My tv just developed a dim area on top of the screen
It is from left to right

TV is under 2 years old and out of warrenty

Recently it would not turn on. Contacted samsung and they agreed to have it repaired but we had to pay labour.

The power board was replaced

Now this new issue

Could this be a bad power board?
I have not contacted samsung yet, just wanted to get some info before I call.



We are not very happy with this TV



the tech had the board replaced in about 10 minutes

I dont remember how many cables went to it

But I did take a pic of the board
This was just back in the 1st week of october









Thank you

[Gv137a]

Re: Samsung 75 LED UN75F6300

I was refered to this site from someone at tomsguide

Here is that thread

http://www.tomsguide.com/answers/id-...un75f6300.html

Just curious if that bar could be caused by the replaced power board

If it is the led string what are the steps to replace it?

Thanks

[budm]

Re: Samsung 75 LED UN75F6300

There are four LED drivers circuits, so check the DCV between chassis GND and the positive leg of each filter caps for the Boost converter circuit to see if they all show the same Voltages.
Pictures provided by shopjimmy.
http://www.shopjimmy.com/samsung-bn4...-led-board.htm

[ReeceyBurger123]

Re: Samsung 75 LED UN75F6300

I think I have seen one these Psus in another thread with a bad solder joint on the transformers. Check for cracked solder joints.

[Gv137a]

Re: Samsung 75 LED UN75F6300

Thank you

I will have to wait till my wife gets home to move the TV.

Just to confirm

Remove the rear center cover

Plug in and test the leg of the capacitors circled in red to ground
Set meter to DC

[budm]

Re: Samsung 75 LED UN75F6300

Thank you

I will have to wait till my wife gets home to move the TV.

Just to confirm

Remove the rear center cover

Plug in and test the leg of the capacitors circled in red to ground
Set meter to DC

Yes.

[Gv137a]

Re: Samsung 75 LED UN75F6300

Thanks

Ill check all the visible solder joints also
Not sure where the transformer is located but ill look at all I can see.

Hopefully have an update with readings

Again. This power board has been replaced by samsung tech and been running since the first week of october

The dim bar just appeared 2 days ago

[budm]

Re: Samsung 75 LED UN75F6300

If one or more has higher Voltage than the rest, that will indicate open LED circuits.

[Gv137a]

Re: Samsung 75 LED UN75F6300

The top one has higher voltage. 340 to 358 jumps

The bottom 3 are steady at 240




What does this indicate?

Would replacing the power board help?

Any futher suggestions?

Thanks

[budm]

Re: Samsung 75 LED UN75F6300

That means there is no load or very light load connected to that C9154 output. So more likely you have LED/LED connection problem in the panel.

[Gv137a]

Re: Samsung 75 LED UN75F6300

Here are the ribbon connectors



Are these the conductors that go to the leds?


Is there any hope for this to be repaired?

[freakaftr8]

Re: Samsung 75 LED UN75F6300

I just got done repairing one of these savage beasts. It's definitely not a job for the faint of heart. There's two connectors on the power supply that run the bottom bank in the top bank of LED strips behind the panel you are upper 3 LED strips are out because one or more LEDs failed on that Bank. The LED strips are backlit so they're not around the edges of the panel there behind the panel and they consist of three LED strips that snap together across from left to right creating one huge LED strip. One of the LEDs failed. I had to repair mind by individually testing each led. There are copper pads on each LED strip that you can use with a voltmeter in diode check mode to test each LED to see if it lights if you get one that beeps short circuit or is completely open and will not like that's your problem. You can get crafty before you open the panel up and take the power supply and remove the screws and carefully Position the power supply up so the bottom connector is now connecting to the top of the panel. This is what I did to tell if it was a power supply issue or not. The very bottom screws on the power supply will touch the top of the power supply mounting bracket so you can screw the bottom of the power supply on to the top mounting screws to hold the power supply in place to do testing to see if the top completely lights up or not. Just be careful of the power supply to make sure that no metal is touching the back of the power supply while you do this. On this model you can disconnect the ribbon cable that goes from the power supply to the main board. The power supply has pull up resistors so the backlighting will automatically turn on when the main board is disconnected. This helps especially when it comes to diagnosing the LED strips.

[budm]

Re: Samsung 75 LED UN75F6300

Those cables go into the inside the panel to the LED strips, yous TV uses edge lit so getting the replacement LED strips may not be easy, and taking the screen that big apart is not going to be easy either.
Notes: I cannot tell if it is edge lit for sure.

[freakaftr8]

Re: Samsung 75 LED UN75F6300

Pics

[Gv137a]

Re: Samsung 75 LED UN75F6300

Thanks guys

Not good news for a plumber

My guess is this will get worst over time?


Any chance the tech disturber anything when he uplugged the ribbons to change the board?

I looked but nothing seems loose.

[budm]

Re: Samsung 75 LED UN75F6300

I think this one is edge lit, http://www.cnet.com/products/samsung-un75f6300/

[Gv137a]

Re: Samsung 75 LED UN75F6300

How can I determine id its edge lit or back lit?

Here are some pics I took













How expensive are the replacement led strips?

This may be something ill have to live with, at least untill it completly fails.
This is discourging, this tv was a major purchase for us. First flat screen I have ever purchased. Learned my lesson. Ill never purchase a samsung product again and whatever I replace it with ill get the extended warranty.


I have an electrician friend at work who is pretty handy with this stuff. ill show him the instructions above and see if he can assist me.

Thanks for the help and suggestions, I really appriciate it.

[budm]

Re: Samsung 75 LED UN75F6300

Hmm, it looks like you can see the nine brown backlights LED strips showing on the back panel of the LCD.
But the review keep saying it is edge lit.
https://www.youtube.com/watch?v=5_eHJOXG6so

[freakaftr8]

Re: Samsung 75 LED UN75F6300

Yes the reviews for my 7100 said it was edge lit also but it is not it is backlit. The louvers on the back side of the metal panel give it away. The backlighting lies within the louvers

[Gv137a]

Re: Samsung 75 LED UN75F6300

Is this the type of replacement part?
http://www.ebay.com/itm/SAMSUNG-UN75...0AAOSwBahVaPb9