Gotta be a T-con problem?? SAMSUNG UN40EH5000

[sugar_ray]

I Got a SAMSUNG UN40EH5000 that's been passed my way

Sound but no picture. In a dark room using a flash light I can clearly see there is picture in the back!!

Is this enough evidence to order a replacement board? or should I diagnose further??

thanks!!

[johns1mj]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Diagnosis further. You have picture and sound but no backlights. If this is correct it sounds like you are not powering up your backlights.

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Good call!!

picture and sound yes. Just confirmed "NO" back lights. Which lands us at the "back light inverter"

this make/model looks like it has the inverter coming off the power supply board as there is no seperate inverter. All I got are TCON board, Main board, PS board and 2 speakers

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Pics

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Pic 2

[dick_barton]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

The led driver output voltage I believe should be 145V@470mA so check the voltages on the pins of the connector which have the wires going to the LEDS.

[Alastair E]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

40" Samsung....

It'll be the LED's....

These things are CRAP!!

[ReeceyBurger123]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

I bet its the Leds' but first before you take the whole Lcd module apart. Check the drive voltage with the Leds unplugged, it should rise to 145v. If it does but collapses the driver is shutting down meaning there is a O/C Led in the screen if it does not rise to 145v the driver is not running meaning it is at fault.

[budm]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

If the LED string has open circuit, it the DCV at the pin 1 d+ on connector CNL802 will be close to 200VDC, around 135V if the load (LEDs) is present.

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Thanks guys will get on this later tonight!! I assume if the string is toast it will be difficult to find replacement LEDs??

[ReeceyBurger123]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Watched my video ?

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Watched my video ?

No man got a link?? My first LED repair!! Done plasmas and LCDs before. I'm all giddy!!

Cheers

[ReeceyBurger123]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Here you go, you can also sub Leds with a resistor or Zenner diode but for best results replace the Led.

https://www.badcaps.net/forum/showthread.php?t=52928

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Right on thanks

[sugar_ray]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

ReeceyBurger123

Thank you my friend!! Very relevant tutorial. While I didn't replace any individual LEDs. Using 2 AA batteries jumpered to Achieve 3 volts I was able to test each bulb, sure enough 2 deadbeats within the string.

Shopjimmy had a replacement set (12 in stock actually) for $39 so I ordered, they arrived and boom!! We have backlight!!

Now for getting the trim plate and bezel back on without damaging the wafer thin panel!!

Final step......dim backlight via remote control

Saved another one from the scrap yard!! Thanks guys for all your input
Terrific forum

[ReeceyBurger123]

Re: Gotta be a T-con problem?? SAMSUNG UN40EH5000

Awesome work