Samsung UN60FH6003FXZA 410vdc going to LEDs

[Captain Blu Ballz]

I'm not sure that the voltage is correct coming off of my power supply board to power the LEDs. There are 4 wires going to the LEDs off of the power supply board and they are marked S+,S-,D+,D-. Testing each terminal to ground is as follows: D+=410vdc, D-=0vdc, S+=7vdc, S-=7vdc. I thought that 410vdc was a little excessive so I purchased another power supply board and I get the same voltages and still no backlight. The tcon board was replaced too as well as the main board (it was a bundled deal). Before I tear into the panel to check the LEDs does anybody have any knowledge of the proper voltages I should be getting at the connector? Thanks for your help

[dick_barton]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

I believe there's a legend on the power supply board giving the voltage for the Led connector (CN802) but I can't read it in google photo's.

Edit
Pictures of your boards would prove helpful
The one capacitor close to the connector looks like its marked as 500V 22uF.

[stj]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

there are no proper voltages, led's are current-drive.
the psu should vary the voltage to regulate the current to the led's

you see it's maximum output probably because the led's are open-circuit or not connected - and so are not drawing any current.

[CapLeaker]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

there are no proper voltages, led's are current-drive.
The psu should vary the voltage to regulate the current to the led's

you see it's maximum output probably because the led's are open-circuit or not connected - and so are not drawing any current.

+1

[stj]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

not sure what the S lines are btw, maybe for a temperature sensor or something!

[ReeceyBurger123]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

there are no proper voltages, led's are current-drive.
The psu should vary the voltage to regulate the current to the led's

you see it's maximum output probably because the led's are open-circuit or not connected - and so are not drawing any current.

+1

[budm]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

You have open circuit in the LED string.
Is this your board?
Samsung BN44-00669A.
D+ is the Anode which the boosted Voltage is fed to the LED string, D- is the Cathode which is the return lien of the LED string and is connected to the PWM Control power MOSFET to and the current sensing resistor for maintianing the constant current and then back circuit Ground.
You are getting 0 on the D- because of the open circuit.
The 'S' is for Sensing, they are not used as you can see how the connection is made at the LED connector.
The LED power supply output Voltage with load is printed on the chart on the board.

[CapLeaker]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

In easy words: You gotta tear into the panel and find the open circuit LED('s) and replace them.

[Captain Blu Ballz]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

Thank You everybody for your quick response. I was hoping it would be something board related but kinda knew I would eventually have to tear into the panel. I hope I don't screw this bad boy up.

Quick question, I've read that when repairing the leds it's best to to replace them all at the same time. If that is the case I'm having a difficult time locating a place that stocks a kit that has all of then sold as a package. Besides jimmys, (out of stock) I can't find anybody else that sells them or has them in stock. Thanks again everybody for your input. I think I've found a new place to hang out. Gotta love fixing stuff except led panels and microwaves. Microwaves have always scared the #$&! Out of me and the Led panel I'm working on now, well, one wrong move and the thing is destroyed.

[Captain Blu Ballz]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

Has photobucket always been riddled with ads? I find it almost impossible to view photos using photobucket.

[Captain Blu Ballz]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

Here are the pictures from the power supply board and the panel once removed. I found one open Led and several shorted Leds. The tv is only 3 years old, huh. The red are shorted and orange is open. Need to find new led strips, any help would be greatly appreciated.

[flocko]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

I would say replace the top pair of LED strips,then cut the 11 good LEDs from these and use them to stack repair the defective LEDs on the other strips. when you have repaired the set turn the back lights down for a longer life

[budm]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

What is your LCD panel model number?
http://www.shopjimmy.com/catalogsear...UN60FH6003FXZA

[Captain Blu Ballz]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

Panel number
Shop jimmy is out of stock

[Captain Blu Ballz]

Re: Samsung UN60FH6003FXZA 410vdc going to LEDs

Update:
Found a full set of leds on ebay. They belonged to a different tv but had the same numbers on the leds themselves. Picture indicates this. I got them to light up no problem but upon reassembly of the tv I heard a slight "tick" and I knew exactly what it was. The screen cracked! ! It wasn't visible until I powered it up though. Lots of time and effort invested in this tv researching, trying to find parts and reading. Boy was I disappointed.


In the pictures below you'll find the numbers I was able to search for to find replacements. You'll notice that your search will come up with a few different tv model numbers but as long as these numbers are in the description you should be golden. Just be careful putting the thing back together. The screen is super thin and made of glass. It will flex to some degree but it is fragile.