Samsung UN60FH6003 black screen, has image

[x_orange90_x]

I have a Samsung UN60FH6003 that the backlights are not functioning. When I turn it on there is no attempt at the lights coming on, just a black screen. I can see the image with a flashlight. Also, when I turn it on the Standby light blinks 6 times.

I haven't been able to inspect or take voltages yet, but by reading a few threads on here about other Samsung LEDs, I gather that it's quite possibly a bad electrolytic or film capacitor, and not necessarily a burned out LED.

It has the BN44-00669A power supply board in it. Attached is a picture of this model. By looking at this picture, what things would I need to check first? I will upload pictures of my actual board as soon as I open the tv up.

Thanks.

[freakaftr8]

Re: Samsung UN60FH6003 black screen, has image

Disconnect the power supply connector to the main board and see if the back lights come up. This model should have pull up resistors in the power supply to allow the backlights to function without the main board Connected

[thoma]

Re: Samsung UN60FH6003 black screen, has image



WAIT UNTIL GET MANUAL APPEARS!!!

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

Disconnect the power supply connector to the main board and see if the back lights come up. This model should have pull up resistors in the power supply to allow the backlights to function without the main board Connected

Finally got around to opening it up. I unplugged the main board from the power supply and still don't have backlights. Were they supposed to come on and stayon? There was the most minuscule little flash of light in the panel whenI first plugged the power cord in with the main board unplugged. Attached are pictures of my actual power supply. Nothing looks out of the ordinary and/or bad. I checked the voltages on the 3 large caps and they were all close to their rating.

[budm]

Re: Samsung UN60FH6003 black screen, has image

https://www.badcaps.net/forum/showth...ht=BN44-00669A
Hook up all the boards back in place.
Leave the black probe on the chassis, red probe on the D+ and then turn on the TV while watching the meter to see how high the Voltage on the D+ goes up to.

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

https://www.badcaps.net/forum/showth...ht=BN44-00669A
Hook up all the boards back in place.
Leave the black probe on the chassis, red probe on the D+ and then turn on the TV while watching the meter to see how high the Voltage on the D+ goes up to.

I will check this tonight. I'm afraid it's sounding like an open circuit.. I hope voltages prove that wrong. I'm imagining the difficulty that would be involved in removing 60 inches of glass without breaking in.

On a side note, I have a 50" Vizio with a cracked screen. How likely would it be that I could use some of its leds to replace burned out ones in the Samsung?

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

I just checked the voltage on that connector. The only wire with any voltage is the last one, D+ @ 425v.

However, if I disconnect the main board, the voltage drops to 400v, and whenI reconnect it the voltage drops again to 292v and will stay there until I unplug the power cord. The backlights will very briefly and dimly flash when either unplugging or plugging back in the main board, but not every time.

[budm]

Re: Samsung UN60FH6003 black screen, has image

425V!, you have open circuit in the LED circuit some where, will not be surprised if you have bad LEDs!
Look at the Voltage chart with load, it is supposed to be 297V 410mA.

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

425V!, you have open circuit in the LED circuit some where, will not be surprised if you have bad LEDs!
Look at the Voltage chart with load, it is supposed to be 297V 410mA.

Did you read my entire post? If I unplug the main board and plug it back in the D+ voltage drops to 292v

[budm]

Re: Samsung UN60FH6003 black screen, has image

"I just checked the voltage on that connector. The only wire with any voltage is the last one, D+ @ 425v." Think about it, you have 425V feeding (D+ pin 1 and pin 2 are tied together) the Anode of the FIRST LED string but you have NO VOLTAGE ON THE RETURN WIRES OF THE LED STRING, PIN 8 & 9 D- is the Cathode of the last string of the LED.
Pin 4 is the Cathode of the first LED string and it is tied to pin 6 which is the Anode of the second LED string, so if the first string has open circuit the you will not see any Voltage on the S pins or the D- pins.
Cap CM861 22Uf 500V is the filter cap for the Voltage booster output circuit, that cap will be charged to very high Voltage if it does not see the load then the protection circuit will kick in then the cap will be discharge by the bleeder resistors.
So are you 100% sure that you do not have any Voltages on other pins of the LED CONNECTOR beside pin D+ 1 and pin 2? Bad data will cause wrong troubleshooting.
You're welcome to replace the power supply board if you want.
Read the link I gave you again if you do not believe me you have open circuit.

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

I'm certain that there was 425v on that D+ wire. The only other wire that read anything was then D- on the other end of the connector, but it bounced between 0 and 1v so I assumed it was negligent and likely false.

Also, the filter cap is reading about 460v with power on.

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

"I just checked the voltage on that connector. The only wire with any voltage is the last one, D+ @ 425v." Think about it, you have 425V feeding (D+ pin 1 and pin 2 are tied together) the Anode of the FIRST LED string but you have NO VOLTAGE ON THE RETURN WIRES OF THE LED STRING, PIN 8 & 9 D- is the Cathode of the last string of the LED.
Pin 4 is the Cathode of the first LED string and it is tied to pin 6 which is the Anode of the second LED string, so if the first string has open circuit the you will not see any Voltage on the S pins or the D- pins.
Cap CM861 22Uf 500V is the filter cap for the Voltage booster output circuit, that cap will be charged to very high Voltage if it does not see the load then the protection circuit will kick in then the cap will be discharge by the bleeder resistors.
So are you 100% sure that you do not have any Voltages on other pins of the LED CONNECTOR beside pin D+ 1 and pin 2? Bad data will cause wrong troubleshooting.
You're welcome to replace the power supply board if you want.
Read the link I gave you again if you do not believe me you have open circuit.

Btw, I have NO voltage on D+ Pin 2, only Pin 1. Likewise, no reading from D- Pin 8, just the questionable 0-1v on Pin 9. The "tied together" must be happening on the other side of the connector? I'm checking the pins at the back of the connector on the power board (right where they enter the plug)

[budm]

Re: Samsung UN60FH6003 black screen, has image

http://assets.shopjimmy.com/media/ca...69a-bottom.jpg
Look at the bottom side of the board yourself and see how the pins are tied together.
But what is your point? I also ready told you that you have OVER 400v FEEDING the Anode of the first LED string and you are not getting Voltages on the Cathode return of the LED string. I am not going to waste my time on this thread any more. You have open circuit so find out where that is.

[x_orange90_x]

Re: Samsung UN60FH6003 black screen, has image

I just wanted to update this thread for reference. I purchased a complete set of backlights from Shop Jimmy and replaced the ones in the TV. TV is now working great! Free 60" TV + $80 LEDs + 2hrs of my time = one hell of a deal ��

Thanks to everyone who answered my questions and have me advice. I've got 3 more TV's that need backlights, and after successfully repairing this one I've got the confidence to tackle the others!