No backlight on Insignia NS-50DR710NA17, need help with voltages

[budm]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

94V is the UL rating for the PCB flammability, nothing to do with Voltage rating of the LED strip.
https://en.wikipedia.org/wiki/UL_94

[Aa1838]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

94V is the UL rating for the PCB flammability, nothing to do with Voltage rating of the LED strip.
https://en.wikipedia.org/wiki/UL_94

Hmm. Well, would the LEDs being somewhat on lend to a bad power supply not pushing enough power? Or could that still be some LEDs/strips out?

[budm]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

Read my post #6 and MUST follow the instruction on step #2 and report the result for the reading of each LED connector pin.
Voltages on CN8601 (Power supply board to LEDs):
+VLED: ?? V
-VLED1: ??V
-VLED2: ??V

[Aa1838]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

Read my post #6 and MUST follow the instruction on step #2 and report the result for the reading of each LED connector pin.
Voltages on CN8601 (Power supply board to LEDs):
+VLED: ?? V
-VLED1: ??V
-VLED2: ??V

Tv Plugged in-no power
+VLED (both): 36.8V
-VLED1: 11.9V
-VLED2: 11.9V

Tv Plugged in-power on
+VLED (both): 53.8V
-VLED1: 5.6V
-VLED2: 5.6V

Tv Plugged in-power on —cn8601 unplugged
+VLED (both): 53.8V
-VLED1: 0V
-VLED2: 0V


No spikes anything over 53.9V

[R_J]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

What is the voltage rating on C8621 and C8623? I think they are 50 volt caps. I believe the voltage you have for +VLED is correct and you have an led string problem.

[Aa1838]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

What is the voltage rating on C8621 and C8623? I think they are 50 volt caps. I believe the voltage you have for +VLED is correct and you have an led string problem.

It's hard to see since they are on the underside glued down but I can see one that says 100V so I would imagine both the same.

[Ukrop]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

Ok guys, I just fixed my Insignia NS-50D40SNA14 - I know, it's an older model but trust me - the same issue:

when powering ON, I see bright INSIGNIA sign and then very dim screen... They call it flashlight test - put flashlight close to the screen and you'll see picture...

I thought it was power supply board. So I went to local repair shop to buy one. But nive guys told me that it's not the board if I see picture. It's failed LED.

So I watched couple videos and took unit apart. Mine had 8 strips of 4 LEDs. One strip wasn't firing. I checked LEDs and sure enough one was bad!!!

Yes, all it takes just one bad LED and whole set goes down...

I found used strip locally for $20, installed it and... it works!

Guys told me it's first thing that goes bad nowadays - cheap LEDs.

Stay safe!

So I am having basically the same issue. I don't know if the other didn't notice or mine is different in this aspect, but my backlight LEDs are coming on somewhat. When the tv is turned on in a dark room you can see the screen but it is extremely dim. With the back cover off you case see light from the holes. It's not a settings issue because I've factory reset it.

I'm just wondering if the power supply isn't supplying enough volts. If you look at the first picture of the LED connector right below the pin out it says 94V. That's the only mention I could find what the led output might be. But I'm unsure if that actually corresponds.

Any thoughts?

[budm]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

Make sure to turn down the backlights level down to as low as possible for all inputs to help extend the life of the LEDs.

[Ukrop]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

Yep, did right away!

Stay safe!

Make sure to turn down the backlights level down to as low as possible for all inputs to help extend the life of the LEDs.

[Vafadb]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

I have the same problem. But this doesn't change when I power on the tv and the voltage are stuck to these:

Tv Plugged in-no power or powered on:
+VLED (both): 36.7V
-VLED1: 10.5V
-VLED2: 10.5V


I powered on the TV using both the physical and remote. No change.

Does it mean that the power board is fried?

[handsworth]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

Having the same problem with the same tv. Flashlight test shows a dim image. Was hard to tell voltage with the tester, so lets go for the backlights. Took the panel off which is glued to the inner bezel and tested the leds individually. My tv had 4 strips with 8 leds each. 1 led was out on 2 of the strips. Just ordered new leds. They about $60

[R_J]

Re: No backlight on Insignia NS-50DR710NA17, need help with voltages

.