Insignia NS-50L240A13 Backlight shuts off

[polaris37]

Hi all, this is my first time posting to any type of forum, but I figured I would give this a try because I have seen a lot of good Q&A on this site. My problem is with a 2012 Insignia LCD TV model NS-50L240A13. When powered on, the display flashes the "Please wait" screen for about 3 seconds and then the backlight goes out. There is still sound and a picture on the screen, but no backlight.
This TV only has 2 replaceable boards, PSB and Main. When measuring the Voltage to the BON pin (which I assume means backlight ON), It is constant at 4.6V from the time the TV is turned on and the backlight briefly comes on until the set is powered off. Does anyone know if this is the correct voltage or where I could find a service manual? I replaced PSB with no difference and am hesitant on spending $100 on another main.
I just purchased this TV in this condition, so I am not 100% sure of the history but the guy who sold it to me said it has approximately 100 hours on it and it sat unused at his office for months and when he brought it home he wasn't able to get it to work. Thanks for any advice!!

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

Please up load good clear pictures of the whole back side of the TV so we can see all the boards.

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

Here's the main. Sorry for the delay, I'm having internet connection problems

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

Here's the PSB

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

How about the pcitures of the whole back side of the TV?
Pictures of the whole board that are not cut out?
BTW, POST #3 does not work.
There must be another LED driver board some where. I cannot tell the setup unless we can see the whole backside of the TV.
http://www.shopjimmy.com/catalogsear...a+NS-50L240A13

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

Here are the pictures that didn't upload before. The only two replaceable boards are the ones in the link you posted

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

It looks like the sub LED driver board may be inside the LCD panel.
Can you give us the LCD panel model number? you can see the stickers on on the panel.

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

V500HJ1-L01 Rev. C1

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

https://cdn.badcaps-static.com/pdfs/...48a1720e2b.pdf

No info regarding the backlights at all.

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

Thanks for the help so far, I figure I might as well tear down further to check the bulbs. Any tips for finding a bad one? I was thinking maybe something happened when he was bringing it home from his office. If there is a bad one are they worth the trouble trying to find a replacement? I have lots of other bulbs from scrapped TVs, but probably not an exact replacement.

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

It uses LEDs for backlights.

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

I finally got around to taking the TV apart further to look at the backlight. It does use CCFL bulbs for the backlight and I found one was broken. Anyone have a suggestion on where I could get a replacement? It is about 42" long. Thank for the help

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

Can we see the pictures of the CCFL assembly? That ribbon cable going into the panel sure does not look like they are made for high Voltage.

[polaris37]

Re: Insignia NS-50L240A13 Backlight shuts off

[budm]

Re: Insignia NS-50L240A13 Backlight shuts off

Holy crap! so they put inverter board inside the LCD panel!
That is why those wires are not High Voltage type wires.

http://www.ccflwarehouse.com/

[nwcs]

Re: Insignia NS-50L240A13 Backlight shuts off

Did anyone ever find out a source for the lamps. I have one here with one broken lamp and would be willing to replace it. I do not seem to have a 50" in store to remove one from.

[shelby5041]

Re: Insignia NS-50L240A13 Backlight shuts off

i have same tv but 39 inch NS-39L240A13 same issue....

have to see if ccfl issue or inverter board issue..are the inverter boards repalceable on the inside of the screen area? cant find any referenace online at all for this model tv online for inverter board

[shelby5041]

Re: Insignia NS-50L240A13 Backlight shuts off

did some more research it does seem the inverter board is repalceable ...will take apart and see if inverter bad or bad ccfl

[shelby5041]

Re: Insignia NS-50L240A13 Backlight shuts off

good news bad news...it was 2 bad ccfl tubes so i just used a wire to jumper it out and then backlights worked..but i broke lcd panel when i reassembled....initially i reassembled and was ok but i could see the lcd panel was not aligned properly so i reluctantly decided to take apart again to realign and yes i cracked the screen when i tiightened the screws and something wasnt lined up properly and screen cracked....i hate dealing with lcd panels..i have done this about 4 times..fixing tv then breaking lcd panel whne putting back together