Insignia NS-55D420NA16 Backlight Problem

[hoangmai]

Re: Insignia NS-55D420NA16 Backlight Problem

I have the same TV with a bad LED strip. I was able to isolate the one bad LED, and I have removed the LED from the PCB. Anyone know where I can find the correct LED for my LED strip so I can fix this strip and get this thing back up and running? LED strip PN: 4C-LB550t-GY2

If you need the set, you can get from here:
https://www.shopjimmy.com/hisense-in...5d420na16-new/

[Toocheap]

Re: Insignia NS-55D420NA16 Backlight Problem

I have the same TV with a bad LED strip. I was able to isolate the one bad LED, and I have removed the LED from the PCB. Anyone know where I can find the correct LED for my LED strip so I can fix this strip and get this thing back up and running? LED strip PN: 4C-LB550t-GY2

[zape]

Re: Insignia NS-55D420NA16 Backlight Problem

Did you use suction cups?
I did as recommended above and everything went well.
I also watched shopjimmy's video and identified the suction cup model they use:
https://www.homedepot.com/p/QEP-4-7-...000Q/100119050

[letienne]

Re: Insignia NS-55D420NA16 Backlight Problem

I found one the LED's was open. When I tried to remove the bad led with a hot plate. The LED broke into parts. The part that was soldered to the smaller pad did not want to unsolder because the connection to board foil are via a plated thru hole and trace. Only 3 of the 11 strips were without bad LEDs. I replaced all of the strips with new ones. When I put everything back together without the back, I got a great picture. I next installed the back and base. When I set the TV on a stand, I powered the TV back on I had a crack in the screen. I don't know if the crack happened after installing the back or after setting the TV on the stand.

[nomoresonys]

Re: Insignia NS-55D420NA16 Backlight Problem

Glad to hear it, nice save.

[zape]

Re: Insignia NS-55D420NA16 Backlight Problem

I fixed mine. It had two failed LEDs, one of them burned in a way it damaged the traces on the led strip so it had open circuit.

[budm]

Re: Insignia NS-55D420NA16 Backlight Problem

Using LED backlight tester to apply voltage to my Insigna NS-55d420NA16, I get 331 volts on the tester. The power supply was disconnected. None of the LED's light. Is the wire between the power supply connector and the first LED strip open?

You have open circuit, I.E. broken wire/s, LED, connector/s between LED strips.

[letienne]

Re: Insignia NS-55D420NA16 Backlight Problem

Using LED backlight tester to apply voltage to my Insigna NS-55d420NA16, I get 331 volts on the tester. The power supply was disconnected. None of the LED's light. Is the wire between the power supply connector and the first LED strip open?

[nomoresonys]

Re: Insignia NS-55D420NA16 Backlight Problem

I would indeed use suction cups.

[zape]

Re: Insignia NS-55D420NA16 Backlight Problem

I'm going to replace the strips on this TV
I see here people damage the screen while trying to do this.
Any advice on how to properly do this and not damage the screen?
Should I use suction cups?

[Wilderone]

Re: Insignia NS-55D420NA16 Backlight Problem

I used suction cups and had no issue taking it off or putting it back on. I was putting it back on until I ordered the new LEDs and I was ready to put them in. I didnt want to leave it all taken apart. It was one of the metal tabs on the side of the TV. Does the screen fit inbetween those tabs? If so it's like the screen grew 1/4 of an inch. It wouldn't go between them so I figured the screen laid on top. Then putting the clips on the side it cracked. I'm still irritated about it though. I was $35 away from having it fixed and would have been a perfect TV for my shop. poof

I find sometimes there is flex in the chassis & plastic panel runners, especially if moved around while the panel is out.
When it comes to this stuff & the more complex strip downs I take a quick photo at each stage to refer back to.
Helps if you have to leave it apart for days & weeks.

[Betviper]

Re: Insignia NS-55D420NA16 Backlight Problem

I used suction cups and had no issue taking it off or putting it back on. I was putting it back on until I ordered the new LEDs and I was ready to put them in. I didnt want to leave it all taken apart. It was one of the metal tabs on the side of the TV. Does the screen fit inbetween those tabs? If so it's like the screen grew 1/4 of an inch. It wouldn't go between them so I figured the screen laid on top. Then putting the clips on the side it cracked. I'm still irritated about it though. I was $35 away from having it fixed and would have been a perfect TV for my shop. poof

[Wilderone]

Re: Insignia NS-55D420NA16 Backlight Problem

Ok. Well this repair was short lived. I just cracked the screen. Arghhhhhhhhhh!!! Little mistakes can sure make a person feel pretty stupid. I was hoping to learn from the original poster. Oh well. Thanks for the advice! I enjoyed tinkering with it and learning though.

Sorry to hear, I've only cracked one but l learnt my lesson to take my time & keep to the same process.
I recently bought a couple of suction cups for larger panels but I find I'm using them everytime now & allows you to lift them evenly.

Chin up there will be another one...

[Betviper]

Re: Insignia NS-55D420NA16 Backlight Problem

Ok. Well this repair was short lived. I just cracked the screen. Arghhhhhhhhhh!!! Little mistakes can sure make a person feel pretty stupid. I was hoping to learn from the original poster. Oh well. Thanks for the advice! I enjoyed tinkering with it and learning though.

[Betviper]

Re: Insignia NS-55D420NA16 Backlight Problem

OK. I never got around to getting you the model number budm and I do apologize, but my LED tester arrived today and I went ahead and got down to the LEDs. 11 strips of 6 LEDs total. I have 6 strips each with 1 LED not working in the strip. 1 strip with 2 LEDs not working and 1 strip that none of the 6 will light up. Should I replace all 11 strips or just one strip and the other individual LED that are not working? Should I be able to test the strips with an Ohm meter to see a short?

[Betviper]

Re: Insignia NS-55D420NA16 Backlight Problem

Man!! Yall Rock!! I will check the model number and post it when I get home feom work. Thank you!

[budm]

Re: Insignia NS-55D420NA16 Backlight Problem

Question. The LED tester says 0-300V. Will that still work for my LEDs since I'm getting a 400V spike? Just not sure howmany LEDs are on my TV. I guess I should just pull the screen because if there are some LEDs out I will need to replace them anyway. With them all exposed I could test each strip individually.

What is the LCD panel model number as printed on the sticker to the LCD panel?

[budm]

Re: Insignia NS-55D420NA16 Backlight Problem

Question. The LED tester says 0-300V. Will that still work for my LEDs since I'm getting a 400V spike? Just not sure howmany LEDs are on my TV. I guess I should just pull the screen because if there are some LEDs out I will need to replace them anyway. With them all exposed I could test each strip individually.

It went over 400V because the LED power supply is not seeing the load, the normal output Voltage is 200V @400mA as printed on the board.
https://www.badcaps.net/forum/attach...7&d=1529354494

[Betviper]

Re: Insignia NS-55D420NA16 Backlight Problem

Question. The LED tester says 0-300V. Will that still work for my LEDs since I'm getting a 400V spike? Just not sure howmany LEDs are on my TV. I guess I should just pull the screen because if there are some LEDs out I will need to replace them anyway. With them all exposed I could test each strip individually.

[Betviper]

Re: Insignia NS-55D420NA16 Backlight Problem

Awesome. I was measuring everything using black to chassis for ground. The LED output I wasn't seeing anything so I tried across the red/white. Thank you for the advice. I have an LED tester on the way. I will report back what I find. This is an awesome site!