Insignia NS-43D420NA16

[scottmet]

I am trying to bring this Insignia tv back to life. As you can see in the pic. I believe I have a toasted smc diode. Wondering if anyone has any Idea what fried it trying to fix it on the component level. Any help would be great. TV turns on has backlight just no image of anykind no menu nothing. Any ideas would be greatly appreciated thanks for your input. This is the power board/ video board /t-con board all in one special.

[WildPuppy]

Re: Insignia NS-43D420NA16

That my friend looks like a blown transistor rather than a diode.
If you look on the back of the board, it seems to be named QG1 (that is next to condensers CG3 and CG1). I would imagine if it was a diode, it would be DG1, not Q.

You need to find a schematic or service manual in order to find out what part used to sit there as from the picture it seems too burnt to read the code.
You may also want to try and find out if other parts are dead, even if they may look visually ok.
Maybe some other more experienced members can help you further with more details or hints.

[dick_barton]

Re: Insignia NS-43D420NA16

If you have a component tester you can test the other Wy 5Gx device close-by to determine what it is. There are lots of cheap component testers out on the market.

[scottmet]

Re: Insignia NS-43D420NA16

Awesome thanks for the tip!!I will pick up a component tester.

[CapLeaker]

Re: Insignia NS-43D420NA16

That little SMD is something like a fet that turns the power to the Tcon and LCD on and off. So there is a massive short somewhere on the Tcon or on the LCD itself. If there is a tcon, it's probably junk and if the panel is shorted it will take a tcon out and the main board like that. Since it is an Insignia to start with, I'd just part it. This isn't a good easy repair, unless one has the proper tools and equipment. Probably there is a small thin Tcon tab bonded on the bottom of the LCD. At least check for shorts there, before you are making any repair attempt on the main.

[dick_barton]

Re: Insignia NS-43D420NA16

Fair point made by CapLeaker. It would be worthwhile removing the faulty device (carefully) and checking the resistance (set off) from each of the 3 pads in turn to chassis to identify if and where there is a low resistance and follow it through to see which other component(s) may be short circuit. You may be lucky.