Insignia NS-42L550A11 no picture

[p2computing]

Hi Guys,

I have an Insignia NS-42L550A11

Here is what I know so far:
TV powers on, blue light blinks for about 8 seconds then stays solid
TV appears to have the backlight turn on after a few seconds
TV backlight appears to turn off when the power is turned off
Sound works properly
Capacitors all appear in decent shape with no leaks

Any help is greatly appreciated!

Board1


Board2


Thanks!

[p2computing]

Re: Insignia NS-42L550A11 no picture

Help me, Budm. You're my only hope!

[budm]

Re: Insignia NS-42L550A11 no picture

Need to see the whole backside of the TV, I cannot see the T-CON board in your pictures.

[p2computing]

Re: Insignia NS-42L550A11 no picture

Ok, once i get home tonight i'll get a photo of it all. Do you want me to remove the protective plates that cover everything as well?

[budm]

Re: Insignia NS-42L550A11 no picture

Ok, once i get home tonight i'll get a photo of it all. Do you want me to remove the protective plates that cover everything as well?

I just want to see the whole back of the TV first to see how many boards there are in your TV.

If you do have backlights but no pictures then we need to find out if we do have DCV at the both ends of the SMD fuse on the T-CON board.
http://www.shopjimmy.com/catalogsear...a+NS-42L550A11

[p2computing]

Re: Insignia NS-42L550A11 no picture

here is the whole back. I removed the panel on the far left board as well.

3rd board


And the whole thing

[budm]

Re: Insignia NS-42L550A11 no picture

OK, the T-CON board is under that metal shield at top middle of the LCD panel, it has two aluminum tapes on it.
There is a cable on the top center edge of the main board that goes to T-CON board.
We may be able to check the DCV on that connector of the main board first before trying to get to the T-CON board, but I will need good clear pictures around that connector of the main board to see if I can locate the power supply pin that feeds the Voltage to the T-CON board.
SHOPJIMMY has some pictures of the main boards but I do not which one that you have.
http://www.shopjimmy.com/catalogsear...a+NS-42L550A11

[budm]

Re: Insignia NS-42L550A11 no picture

This looks like your board:
You need to check DCV between the chassis and each end of the resistor R495 which is close to pin one of the connector CN408, there is also a cap C4E4 close by. Q403 looks to be the switched POWER MOSFET for supplying the Voltage to the T-CON board.
picture by shopjimmy.

[p2computing]

Re: Insignia NS-42L550A11 no picture

I'll confirm that board in the morning and try to get you DCV readings. Thanks again!

[p2computing]

Re: Insignia NS-42L550A11 no picture

Budm, are you able to mark with some sort of color on that image exactly where i should be touching the positive lead from my fluke?

[budm]

Re: Insignia NS-42L550A11 no picture

Please the pix. Make sure the TV is turned on.

[p2computing]

Re: Insignia NS-42L550A11 no picture

That reads 12v DC exactly

[p2computing]

Re: Insignia NS-42L550A11 no picture

The top of that same resistor reads 0v DC.. Nothing coming through it

I tested, on the T-conn board , the second pin from the left coming in from the main board, and read 12v DC

[p2computing]

Re: Insignia NS-42L550A11 no picture

Update: After having the TV powered on for about 20 minutes, i am now able to bring up the menu and view it just fine. I assume this is because a particular chip or cap is going bad, requiring it to warm up for quite a while?

[budm]

Re: Insignia NS-42L550A11 no picture

That reads 12v DC exactly

OK, so the main board is sending the VCC to run the T-CON, you may want to reseat the connector on the T-CON board, also tight up the mounting screws of the T-CON board, main board, and power supply board.

[p2computing]

Re: Insignia NS-42L550A11 no picture

I'll do that, but would that cause the TV to require a "warm up" period? After it's warm, i can power it off and back on with zero issue.

[budm]

Re: Insignia NS-42L550A11 no picture

If it starts working when warm up. You will need to check the Voltages when it is not working to see what is missing, that will give you the clue on where to start. Since when the TV does not work, you do have backlights but no images on the screen, then I would monitor that 12VDC feeding the T-CON to see if that disappears when the TV is not working. But I would still want you to do as I suggested in post 15.

[p2computing]

Re: Insignia NS-42L550A11 no picture

Will do once i get home tonight. Thanks again =)

[p2computing]

Re: Insignia NS-42L550A11 no picture

I re-seated the connection, and tightened all the screws holding the boards to the chassis. The TV started up great without warming up! Thanks for all the help =)

[budm]

Re: Insignia NS-42L550A11 no picture

Glad to hear it is working but if it goes out again, check that 12VDC right away to see if it goes away, you may have to check right at the fuse on the T-CON board.