Insignia 4k NS-50DR710NA17 troubleshooting

[captainKKK]

Insigna NS-50DR710NA17

Plug to AC, small blue power indicator light at center bottom illuminates. Only using flashlight test, Insignia emblem in center of screen for 90 seconds and then nothing. Power button pressed and still using flashlight screen test, the entire Roku, 4K menu is shown. Never does the back light show any light., even in dark room.

Boards are these: https://www.shopjimmy.com/insignia-n...-1182036900530

wifi unplugged

Voltages on CN9103 (Power supply board to main logic board):
Pin 1, DIM: 1.84 V
Pin 2, BL/OF: 3.23 V
Pin 3, PS_ON: 3.317 V
Pin 4, NC: 0 V
Pin 5, GND: 0 V
Pin 6, GND: 0 V
Pin 7, GND: 0 V
Pin 8, GND: 0 V
Pin 9, +12VA/+16VA: 15.9 V
Pin 10, +12VA/+16VA: 15.9 V
Pin 11, +12V/+16V: 15.9 V
Pin 12, +12V/+16V: 15.9 V
Pin 13, +12V/+16V: 15.9 V
Pin 14, +12V/+16V: 15.9 V
Pin 15, +3.5V/+5V: 0 V
Pin 16, +3.5V/+5V: 0 V

Tv Plugged in-no power
+VLED (both): 36.9V
-VLED1: 16.8V
-VLED2: 16.8V

Tv Plugged in-power on
+VLED (both): 53.8V
-VLED1: 9.1V
-VLED2: 9.1V

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

referenced https://www.badcaps.net/forum/showth...ht=50DR710NA17

Please advise with additional testing or verdict . Thanks

[neilc6]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

Backlight issues are 99% the backlights themselves. If they fail open circuit, then you won't get a flash. Best tool for troubleshooting is a LED tester.

[jjanssen7]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

Especially for that particular model, BTW. The good news is that there are many other models that your LCD panel will fit. Mostly Sharp models, but some Toshiba's too. Should be a cracked screen 50" 4K Sharp or Toshiba for sale for cheap nearby... depending on the model number it's a direct replacement (move the Tcon with the screen just to sure...)

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

next

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

The thing that bothers me is that D8616 and D8614 heat sink is stone cold and so is the heat sink for Q9103. Pls zoom the SJ pics referenced and advise.

[jjanssen7]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

Let's put it this way... I have had 30 or 40 of that Model come through my place and 100% of them had burnt out Leds. Confirm yours with LED tester?

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

What is the most frequently used backlight LED color, voltage and model number? Example see https://es.aliexpress.com/item/10050...:%222908%22%7D

[neilc6]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

With backlight failures, it is best to replace all the strips with new. Looks like they are available for you model and not too expensive. All the LEDs have wear and they will eventually fail. Just had a Sharp 50LB come back almost at the two year mark with the bad LEDs replaced with used strips and the backlight turned down.

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

Find your correct backlights replacements from the panel Sticker in your TV instead of your model may product greater sources, like in this video: https://www.youtube.com/watch?v=13CUchXLjNo. But the pros in here already know this.

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

I would still like to get a roll of 100 LED for this fix just in case, but I do not know the right voltage or model of LED to get.....any advise?

[alfatv]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

I would still like to get a roll of 100 LED for this fix just in case, but I do not know the right voltage or model of LED to get.....any advise?

You are very demanding. The members here often can't find replacements even after desoldering LEDs and seeing how they look like. Having variety of types on hand sometimes helps. If you don't want to take TV apart, you either need to do your own research or play lottery.

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

No demands any where in this thread. Just seeking advice from the pros, who have already been very helpful. Thanks.

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

Got all new backlights from Aliexpress for $26.03, installed and works perfect. Mark as finished. https://www.aliexpress.com/item/1005...3da24c4dCboxKg

[dskall]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

As far as led's you really need to desolder from board identify voltage and polarity, and pad size. Best with led tester. I used to replace individual led's. I always had a problem with color temps. New ones where always a bit on the yellow side.

[captainKKK]

Re: Insignia 4k NS-50DR710NA17 troubleshooting

Yeah I thought about that and for less than $27 I decided to replace ALL the whole strips at the same time with these new ones and forget the hassle of doing individual ones, especially since the old ones were likely to fail soon too.