Author |
Message |
Bnystrom
Joined: 11 Mar 2017 Posts: 2 Location: New Hampshire
|
Posted: Sat Mar 11, 2017 2:13 pm Post subject: Samsung UN40EH5000FXZA - sound, but no picture |
|
|
The panel appears to be fine (flashlight test), but the backlight is not working. The power supply board shows no evidence of component failure. I get 216V at pins 1&8 and 2&7 with the TV powered on, zero when powered off. I've got 5V between JP813 and JP812 (or ground).
Testing the LEDs individually revealed a single dead LED in the center of the top strip. All of the others are working. Is that enough to shut down the entire array?
Any suggestions would be greatly appreciated.
Thanks
Brian |
|
 |
Google
|
Post subject: Advertisement |
|
|
|
 |
JTS1957
Joined: 21 Jan 2009 Posts: 2395 Location: Far, Far Away
|
Posted: Sat Mar 11, 2017 4:07 pm Post subject: |
|
|
Yes, a single LED can stop all.
I'd suggest applying enough voltage to the driven end to light the whole strip.
If/When done repairing, be sure to decrease backlight intensity to extend replacement's lives. |
|
 |
Bnystrom
Joined: 11 Mar 2017 Posts: 2 Location: New Hampshire
|
Posted: Sun Mar 12, 2017 7:37 am Post subject: |
|
|
JTS1957 wrote: | Yes, a single LED can stop all. |
Excellent, now I know what I need to fix it. Thank you!
One thing I'm curious about is the voltage to the LED array. There are a total of 38 LED at 3V each, so I would expect the voltage to be around 114V. However, I'm getting 216V+ at the connector. Is there additional resistance that must be overcome or something? |
|
 |
|