Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

[frafreg]

When I plug the set in the front LED flashes 6 times and goes out. No sound no picture. The T-Conn board has 3 blue LEDs turned on. The main board has one large chip with a heat sync which gets hot after a while. Seems a little hotter than it should be since it has a heat sync. No other visible signs of bad caps or burned components. I tried disconnecting the main board from the power supply but the LED still didn't light. How can I determine if the problem is the power supply or the main board? What is the blink code for 6 flashes? Thank you in advance for your help. I really appreciate it!

LED connector (from chassis ground)
1 D+ 150v
2 S- 137v
3 no connection
4 S+ 137v
5 D- 0

Main Board connector
1 12.5v
2 3.3v OD_UD
3 12.5v
4 1.6v BLU_PWM
5 12.5v
6 3.3v PWR ON/OFF
7 12.5v
8 Gnd
9 Gnd
10 0

[budm]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

You have 0V on the Cathode return line D - of the LED string, that means the second LED string has open circuit that is why the Voltage jumps up to 150V.
Pin 1 and 2 is for the first LED string, pin 4 and 5 is for the second set of LED string, the two string are connected together in series.
D + is the Anode of the first LED string which is connected to the output of the boost converter circuit, S- is the Cathode of the first LED string and it is connected to S + which is the Anode of the second LED string, the the D - is the Cathode of the second LED string which is connected to PWM controlled and the current sensing resistor to GND.

BTW, you count the connector pins wrong, the exposed pins that you can see from the top side are the ODD number pins, the EVEN number pin you will have to probe from the wire entrance of the connector. The pin label charts has ODD and EVEN column.
Is this your power supply board? BN44-00768A
http://www.shopjimmy.com/samsung-bn4...-led-board.htm

http://www.shopjimmy.com/catalogsear...ung+UN32H5203A

[frafreg]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

Thanks for your reply budm. Yes, that is my power supply board.

Would the second LED string being an open circuit be the reason why the LED flashes 6 times without powering on?
Is there some way I can make the set turn one with just one strip just to test it, before going any further? Thanks!

[budm]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

The 6-Flash of the LED has nothing with the backlights, Samsung does not have blinking error code.
You can try using 220 Ohms 10W resistor between GND and S -, that will let the backlights to come on for seconds so you can see if you will see any image on the screen or not.
If you do not have the resistor, you can use 15W incandescent lamp instead.

[frafreg]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

I used the 15 watt bulb and the set turns on and looks like it is working OK.
Can I repair the open LED strip or is it advisable to just replace both strips?

Thank you again budm! I really appreciate your help.
Frank

[budm]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

I would replace both strips at the same time since you do not want o open up the screen more than once because it can get damaged easily.
BTW, do the backlights come on and stay on? How bright is it?

[frafreg]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

The backlights came on and stayed on but I only tested it for about 10 minutes. The screen was not at full brightness but that makse sense. I used an HDMI input to make sure everything looked OK.

[frafreg]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

I removed the display to see how many LEDs were still working. The bottom LED strip is dead and there are only 5 LEDs still working on the top LED strip. I made sure I had the correct LED strip part number, D3GE-320SM1-R2[13.07.10] and I ordered two new ones.

Is this a common problem with these sets or was the problem caused by the backlight adjustment being set to the maximum level which caused the LEDs to burn out?

Thanks!

[budm]

Re: Samsung UN32H5203AFXZA no backlight-LED flashes 6 times

It is common failure in most TV with LED backlights, they drive the LED at the max spec and poor thermal management.
When you get it working make sure to turn down the backlights on all input mode to about 50%.