Insignia NS-48D510NA15 no backlight

[mjwarden82]

First thread posted here! I have an Insignia LCD tv that once turned on, the standby light blinks 5 or 6 times and does not have the backlight on. I opened it up and couldn't find a backlight inverter, but rather just a power board, main board and T-con board. I figured that the backlight inverter was built into the power board, so I went ahead and ordered a replacement. Well, it turns out that did me no good so I'm looking for ideas on what else it could be. I popped the front bezel off and had the panel out, but promptly put it back in as I didn't want to mess anything up without consulting you guys first. I figure that it has to be some LED's out on the strips, but those aren't very easy to get at and I'm hoping somebody on here has some experience with this particular set. This TV is just over a year old and unfortunately out of warranty. The power board I ordered is supposedly new from PartStore and fyi when turned on it does pass the flashlight test and the sound does work. I have attached pics of the power board, the back panel and the wires that go from the power board to what I believe are the LED strips for the backlight. Thanks in advance for any tips!

[budm]

Re: Insignia NS-48D510NA15 no backlight

Your TV uses one LED string backlights LED, it does not have backlights Inverter, you can see the small white connector for the LED with Black and white wires that is connected to the power board and another end goes into the LCD panel.
Before turning in the TV you will leave the black probe on the chassis, and leave the RED probe on the White wire terminal, then turn on the TV, take the reading and wait a few minutes before turning the TV OFF to see how low the Voltage will drop down to, then do the same thing again with the Black wire terminal.
Do that again without the LED connector of the power supply board.

[mjwarden82]

Re: Insignia NS-48D510NA15 no backlight

Ok, so leave the connector with the black and white wires plugged in first, take voltage reading, then unplug connector and test voltage on the terminal on the power board? I'll give that a shot when I get home. Thanks!

[budm]

Re: Insignia NS-48D510NA15 no backlight

Ok, so leave the connector with the black and white wires plugged in first, take voltage reading, then unplug connector and test voltage on the terminal on the power board? I'll give that a shot when I get home. Thanks!

That is correct, so 4 tests total.

[ReeceyBurger123]

Re: Insignia NS-48D510NA15 no backlight

Think we know the issue here lol, when you find that the Psu is good (hopefully) I will link my video on how to repair Led backlights haha

[budm]

Re: Insignia NS-48D510NA15 no backlight

Think we know the issue here lol, when you find that the Psu is good (hopefully) I will link my video on how to repair Led backlights haha

Will not be surprised if it is LED problem, just over a year old! sad.

[mjwarden82]

Re: Insignia NS-48D510NA15 no backlight

Great! Thanks for all the advice guys, I really appreciate what you do. Also, I got too curious and had to look up that youtube video... great tips in there!

[mjwarden82]

Re: Insignia NS-48D510NA15 no backlight

That is pretty sad... Although it hurts a little less knowing that all told so far I only have about $30 invested in it, they were going to dispose of it at work but I snagged it (with their approval of course).

[JELO]

Re: Insignia NS-48D510NA15 no backlight

Hello All,
I am now having the same issue, found this post thru google search!

I just wondered if the issue was fixed, and how?

I've called 3 tv repair places so far, no one is interested.

Do I need to order the backlight inverter board to fix??

Thank you, hoping someone can help!

[dick_barton]

Re: Insignia NS-48D510NA15 no backlight

Have you carried out the tests as described in post #2 and what results did you get?

[mjwarden82]

Re: Insignia NS-48D510NA15 no backlight

I ended up ordering some backlight strips off ebay and that did the trick for me

[bplatzmarcum]

Re: Insignia NS-48D510NA15 no backlight

Okay so I am having a similar problem. I measured the voltage and it is 409v with or without the led strips connected. I am confused by that, isn't it supposed to be 0 volts with the LED connected if they are bad?

Any help would be greatly appreciated!

[bplatzmarcum]

Re: Insignia NS-48D510NA15 no backlight

I should say black is 409V and white is 0V

[budm]

Re: Insignia NS-48D510NA15 no backlight

The black lead is the feeding Voltage to the Anode of the LED string.
You have open circuit in the LED string.

[razsizz]

Re: Insignia NS-48D510NA15 no backlight

Hey guys, found this forum after having a similar issue. The TV turns on, sound works, but the screen is all black. It briefly came back to a very dim life after I left it unplugged for a day or two, but then back to nothing.

Anyway, I did the multimeter tests and got:

Wires Connected:
Black Terminal - 399-400
White Terminal - 0

Disconnected:
Black - 398-399
White - 0

I left the TV for a half hour or so each time and got no variance aside from that one volt.

So, I assume that means the LED strip is bad? I ordered a new one and it should be here next week. Any other input or advice on replacing the strip once it comes in? I have a pretty decent crafting skillset, but electronics is not my forte. Anything else you guys can tell me would be greatly appreciated.

[R_J]

Re: Insignia NS-48D510NA15 no backlight

Be VERY carefull when disassembling the lcd panel. it is very fragile! Also either mark, or remember the sequence and orientation of the diffuser sheets behind the lcd panel, and again, Be VERY CAREFULL re-assembling the panel.

[budm]

Re: Insignia NS-48D510NA15 no backlight

Take good pictures in case you forget how it goes back together.

[Models]

Re: Insignia NS-48D510NA15 no backlight

Where exactly am i supposed to put my test leads. I am never getting any constant voltage on either of the points.

[Models]

Re: Insignia NS-48D510NA15 no backlight

Ok i changed the settings on my metre with the led connector connected i get a reading of 226 with it not connected im getting 320. And 0 on white side for both tests. Whats going on. Also the board makes a pretty decent buzzing sound ?????? Also when i ohm out the led strip wires it reads open ???

[Topcat]

Re: Insignia NS-48D510NA15 no backlight

I was given one of these sets today. Seems same scenario. With the connector plugged in, across the white & black wires to the LED backlight I've got +340v using BLK as positive, WHT as negative. From GND to black, I've got +240v. From GND to white I've got -100v using white as positive. I get the same voltages with the connector unplugged. The flashlight trick reveals my color bar pattern in the background, but of course no backlight. Looks like LED strip surgery....being a freebie, I've got nothing to lose....but what's everyone's favorite LED strips to order?

This is what I've found so far....probably about as good as it'll get. https://www.ebay.com/itm/274192154303