Insignia NS-L37Q-10A No screen display

[shumiron]

I have been incorrectly posting to an existing thread that is for a different model Insignia. I am now going to post all the facts I have regarding the NS-L37Q-10A I am trying to fix.

Plug in TV and red light glows. Press ON button or turn on with remote and red light changes to blue. So remote sensor appears to be working.

"Please Wait" displays on screen for a few seconds - not very bright.

Screen does appear to have some backlight when viewed in dark room. Light appears to be at top center, not all around the perimeter.

I have checked voltages at PS connector that goes to Main Board. and all voltages are correct at PS end. Have not checked at MB end of cable.

At one point I connected an XBox thru HDMI and heard some audio. But, I was trying to change inputs on the TV and pressed the button too soon. Now I can't get back to where I hear audio.

BudM has been trying to help and suggested I should start a thread - This is it!

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

Where is the inverter board on this TV. I can't seem to find it

[budm]

Re: Insignia NS-L37Q-10A No screen display

You power supply-inverter board combo.
So you do have backlights but no pictures on the screen, then you need to find out if you do have 12VDC at both ends of the SMD fuse on the T-CON board with ref to chassis GND.
The fuse is the white fuse to the right of the LVDS connector on the T-CON board.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

So the inverters are on the power board, correct? No separate inverter board. I do have 12 V on both sides of the fuse on T-Conn board. I can see the backlight light up after a few seconds when I turn on TV. Also there is a blue LED on T-Conn that lights up momentarily (LD2). The backlight I can see goes out after a few seconds and then the blue LED also goes out. For clarification, I am looking at the chassis side and can see light at some of the cutouts along bottom of chassis. The light must be on when it is displaying "Please Wait". So it appears the backlight does not stay on when "Please Wait" goes away.

[budm]

Re: Insignia NS-L37Q-10A No screen display

"So the inverters are on the power board, correct?" Yes.
OK, for less confusion, that backlights did come on and then go off but the BL-ON is still present, if that is the case, we need to look at the inverterter section of the power supply board, hopefully it will not be the lamps problem.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

Where is the BL_ON pin? Is it on the main PS connector at the other end from the two 5 V pins?

[budm]

Re: Insignia NS-L37Q-10A No screen display

It should be one of the pin of that white connector that goes to the main board, I cannot see if there is any pin labels on that connector, the picture is not in focus.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

OK. Sorry about the picture. There are 2 pins on main board end of the PS cable that are marked BL and one pin next to them that is marked BR. Both BL pins have approx 3.3VDC and BR pin has approx 12VDC.

[TechGeek]

Re: Insignia NS-L37Q-10A No screen display

I would trace that 12V and see if it goes to that fuse. If it does I would also check the path AFTER that fuse and check all the components after the fuse and see if goes almost to the display or to the display.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

BudM - What are you referring to regarding 'the lamps problem'?

[budm]

Re: Insignia NS-L37Q-10A No screen display

Backlights lamps.

[budm]

Re: Insignia NS-L37Q-10A No screen display

http://assets.shopjimmy.com/media/ca...dtv8ne1ac9.jpg

The connector on the power supply-inverter board has labels for the pins. Please give me the listing of the pins.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

So are you saying that the backlight lamps may be faulty.....if so I don't understand why they will come on for a few seconds then go off. My thinking is if they come on at all then that means they are functional, something is not allowing them to stay illuminated. By the way - are you located on the West coast? I am in San Diego.

[budm]

Re: Insignia NS-L37Q-10A No screen display

Because lamps do wear out, the connections to lamps can be bad. It will only take one bad lamp to shutdown the inverter circuit, it can also be bad inverter transformers, the inverter circuits, etc.
Examples of bad CCFL, bad wiring:
http://s807.photobucket.com/user/bud...?sort=3&page=1
BTW, if your lcd panel is LC370WUE-SBB1, then it uses EEFL for backlights and the sockets for the lamps are used for lamp connections.

You should also read this:
https://www.badcaps.net/forum/showthread.php?t=10419

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

From the top down on PS Board they are:

1 - O/F
2 - DIM
3 - +12V
4 - +12V
5 - GND
6 - GND
7 - GND
8 - 24V
9 - 24V
10 - PS_ON
11 - +5V
12 - +5V

On Main Board - Pin 1 is at the bottom

12 - +5V
11 - +5V
10 - PS
9 - 24V
8 - 24V
7 - GND
6 - GND
5 - GND
4 - P12V
3 - BR
2 - BL
1 - BL

Top and bottom reference is the TV top and bottom oriented as in the chassis picture; the bottom is closest to me standing at the bench.

[budm]

Re: Insignia NS-L37Q-10A No screen display

"From the top down on PS Board they are:

1 - O/F
2 - DIM
3 - +12V
4 - +12V
5 - GND
6 - GND
7 - GND
8 - 24V
9 - 24V
10 - PS_ON
11 - +5V
12 - +5V

So tell me what DCV you have on ALL those pins (except the GND pin) after the TV goes black.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

1 - o/f = 3.31
2 - dim = 3.35
3 - +12v = 12.3
4 - +12v = 12.3
5 - gnd
6 - gnd
7 - gnd
8 - 24v = 25.2
9 - 24v = 25.2
10 - ps_on = 4.73
11 - +5v = 5.2
12 - +5v = 5.2

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

hello Budm - Do these voltages look OK? Can I check the voltage on the two single wires coming off the transformers and going into the chassis - I think they must be the power for the CFL bulbs.

[budm]

Re: Insignia NS-L37Q-10A No screen display

1 - o/f = 3.31
2 - dim = 3.35
3 - +12v = 12.3
4 - +12v = 12.3
5 - gnd
6 - gnd
7 - gnd
8 - 24v = 25.2
9 - 24v = 25.2
10 - ps_on = 4.73
11 - +5v = 5.2
12 - +5v = 5.2

They are all correct, so we need to look further why the backlights come on and shut down.

[shumiron]

Re: Insignia NS-L37Q-10A No screen display

I tried measuring the voltage coming from the pwr supply on the two single wire connectors adjacent to the two black transformers in the upper left corner (ref the picture I posted. I have a industrial autoranging digital VOM and whatever happens on that connector, it blows the meters mind. I tried both DC and AC ranges and the meter shuts itself down after a couple seconds of wild fluctuation. I think these are the wires powering the CFLs. So I don't know what is going to the bulbs.