Insignia NS-LCD47HD-09 no picture

[rod30]

I have come to a dead end on this and would like some help. Most of the repair I have done has been bad caps, so I don't know where to go with this one. When I check the voltages at the power board and at the main board they are all OK. I did the flashlight test and did not see an image. So I replaced the T-con board with a used one that I believe to be good and still no picture. Any help would be appreciated.

[ReeceyBurger123]

Re: Insignia NS-LCD47HD-09 no picture

Do you get backlights ? Common issue with this chassis is the mobo not sending the Blon signal meaning backlights wont fire on.

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

The screen never lights up.

[ReeceyBurger123]

Re: Insignia NS-LCD47HD-09 no picture

Ok do you have a DMM ? No point just throwing boards at it, you need to diagnose this properly.

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

I do have a digital multimeter. I assume that is DMM?

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

Since I am not getting back lights I did some checking on the board. It seems as if the fuse located at C55 in the attached picture. On one side I get 24 volts, on the other side 0. So what would have caused this fuse to blow?

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

The test points at the end of the ribbon cable have no voltage. All of the white fuses on this board have 24v and are good. I did not find voltage at any black fuse.

[budm]

Re: Insignia NS-LCD47HD-09 no picture

You need to check the BL-ON signal on the inverter board, you need to remove that black cover so you can see if the pins of those two big white connectors are labeled or not.

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

Thank you for the reply. Yes, voltages are as follows.....

VBL-24.4v VBL-24.4v
VBL-24.4v VBL-24.4v
VBL-24.4v VBL-24.4v
VBL-24.4v VBL-24.4v
VBL-24.4v VBL-24.4v
GND GND
GND GND
GND GND
GND GND
STATUS-not used
E_PWM-not used
I_PWM-3v
BLON-3v

[budm]

Re: Insignia NS-LCD47HD-09 no picture

OK, you do have all the needed signal for the inverter board to function, so I need to see good clear picture of the inverter board.
Thanks for the nice and clear picture in post 9.

[budm]

Re: Insignia NS-LCD47HD-09 no picture

BTW, that small black fuse with '20' printed on top shows < 1 Ohms of resistance?
https://www.badcaps.net/forum/attach...3&d=1455065642

[budm]

Re: Insignia NS-LCD47HD-09 no picture

Since I am not getting back lights I did some checking on the board. It seems as if the fuse located at C55 in the attached picture. On one side I get 24 volts, on the other side 0. So what would have caused this fuse to blow?

Can you please point out to the fuse? What is printed on the fuse? I see C55 but I do not see any black fuse close by.
https://www.badcaps.net/forum/attach...1&d=1455064479

[Caleb]

Re: Insignia NS-LCD47HD-09 no picture

"It seems as if the fuse located at C55 in the attached picture"
The label is a giveaway, not a fuse rather a ceramic capacitor
You can see the label for the fuse on the inverter board pic but not the fuse are those fuses good?

[budm]

Re: Insignia NS-LCD47HD-09 no picture

"It seems as if the fuse located at C55 in the attached picture"
The label is a giveaway, not a fuse rather a ceramic capacitor

Ah I see what he is saying now, he thinks C55 is a fuse. I also wonder what he means by this also in post 7: I did not find voltage at any black fuse.).
There is only one black fuse with '20' printed on top.

[Caleb]

Re: Insignia NS-LCD47HD-09 no picture

I think he didn't test that fuse yet even though you circled it

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

You are correct, some things I thought were fuses were not. I have tested both of the large white fuses located near the capacitors and have 24v on both sides. Also I have 24v at the + leg of each capacitor. I am somewhat new at this and will try to do better. Please don't give up on me.

[budm]

Re: Insignia NS-LCD47HD-09 no picture

You need to test that small black fuse I show in the picture in post 11.

[rod30]

Re: Insignia NS-LCD47HD-09 no picture

The black fuse with "20" on the top. Has 24v on the side toward the connector and 1.2 on the other side. Wow, that is small. I have never replaced anything that small. Please give me some idea where I get a fuse like that and how is the best way to replace it. Also, it blew for a reason. Have you had good results just replacing one and not being to concerned why it's blown?

[budm]

Re: Insignia NS-LCD47HD-09 no picture

That black fuse is the common failure fuse used in CMO inverter board, I use PICOII through hole fuse in its place, done so many of them without having the TVs come back with the same blown fuse.

[Caleb]

Re: Insignia NS-LCD47HD-09 no picture

You can test (in ohms) from the side that gets no voltage to ground and reply back.

Sometimes fuses fatigue over time and there is no fault just an open connection. If the ohm reading is in kohms you probably just have a failed fuse, if its in tens or hundreds of ohms you have a fault that blew the fuse.

btw sorry budm you replied as I was typing : )