Insignia NS-LCD15-09 -- Won't Turn On

[PohTayToez]

The Pictures

Power Board
Main Board

Unless I'm missing something, it seems to be the back light is powered directly by the power board with no separate inverter board.

When plugged in the status light goes red. When you hit the power button the light turns blue for a split second then goes out and starts blinking red. It blinks five times and then on the sixth blink it stays red and you can try and turn it on again with the same results.

There are no visibly failed capacitors.

Here are the readings I got off of the power board output to the main board:
+12V = 12.59v
GND = .00v
+5V = 5.12v
ON/OFF = .00v
DIM = -.03v

Not sure what to do next... should I start testing voltage regulators? Also I was not able to identify any sort of fuses to be tested.

[tom66]

Re: Insignia NS-LCD15-09 -- Won't Turn On

ON/OFF and DIM are low.
Suspect the main board.

There are many regulators on it. Please test them. https://www.badcaps.net/forum/showthread.php?p=300999#

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Should I be able to get a reading off of the regulators since it won't come out of standby? I was only able to get a measurement off of one:

U706
885
17-33L
Pin 1 = 0.00v
Pin 2 = 3.28v
Pin 3 = 5.12v

Also, random question but a lot of the regulators are labeled with what looks like a backwards "C" followed by "11". Can you tell me what that means?

[tom66]

Re: Insignia NS-LCD15-09 -- Won't Turn On

OK, can we have a picture of the main board?

Can you acquire some 1k ohm resistors? We can make the backlight and dim voltages high, so the screen can be tested.

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Main Board

I'll have to see what I can do on the 1K ohm resistors, I may have to order some. Is there any other testing I can do in the meanwhile?

[budm]

Re: Insignia NS-LCD15-09 -- Won't Turn On

What resistor values do you have?

[tom66]

Re: Insignia NS-LCD15-09 -- Won't Turn On

So what do the other regulators measure on the board? Zero, nearly zero (<0.1V)?

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

What resistor values do you have?

I do not have any resistors at all, I might see if I could salvage some but I will probably just order them. How many do I need?

So what do the other regulators measure on the board? Zero, nearly zero (<0.1V)?

They all measured at less than .01v (i.e. I had the multimeter set to measure out to two decimal places and everything read at .00v)

[budm]

Re: Insignia NS-LCD15-09 -- Won't Turn On

You may need at least 2, one for the Power supply ON (PS_ON), and one may be for the Backlights ON (BL_ON/INV_ON/OFF) just in case, but from the l0oks of it, the power supply is an always on power supply, so you just need 1 for the ON/OFF (BACKLIGTS ON/OFF control).

[budm]

Re: Insignia NS-LCD15-09 -- Won't Turn On

By the way, I can see at least 3-pin devices that look like Voltage regulator ICs that you need to check. So far I agrre with Tom that you do have bad main board problem and not sure if it will be worth fixning or not for this small TV, it will not be too bad if it onlt has bad regulators, anything other than that will require more in depth troubleshooting and times which I do not know how mush time you are willing to spend on component level troubshooting, beside, do you have the tools to do surface mounted repair?

[retiredcaps]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Main Board

I'll have to see what I can do on the 1K ohm resistors, I may have to order some.

A couple of things.

1) We prefer pictures attached following the instructions in my sig file exactly for a number of reasons.

2) Using the above method, tom66 would have seen the main board as a thumbnail in post #1.

3) To turn on PS_ON or BL_ON, you can use a CR2032 3V battery or 2 AA batteries in series.

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

A couple of things.

1) We prefer pictures attached following the instructions in my sig file exactly for a number of reasons.

2) Using the above method, tom66 would have seen the main board as a thumbnail in post #1.

3) To turn on PS_ON or BL_ON, you can use a CR2032 3V battery or 2 AA batteries in series.

Sorry about the picture, I figured I'd take it at the highest resolution for max detail. As for #3, will that allow me to test the voltage regulators? Someone else said they thought it might be an "always on" PSU. How would I need to hook up the battery?

By the way, I can see at least 3-pin devices that look like Voltage regulator ICs that you need to check. So far I agrre with Tom that you do have bad main board problem and not sure if it will be worth fixning or not for this small TV, it will not be too bad if it onlt has bad regulators, anything other than that will require more in depth troubleshooting and times which I do not know how mush time you are willing to spend on component level troubshooting, beside, do you have the tools to do surface mounted repair?

Right now I have only been able to test in standby and in standby only one of the regulators is getting power. As for replacing surface mount components that will actually be the easy part for me.

[retiredcaps]

Re: Insignia NS-LCD15-09 -- Won't Turn On

As for #3, will that allow me to test the voltage regulators?

No, it will only do the test tom66 mentioned in post #4, namely test the screen comes on.

Someone else said they thought it might be an "always on" PSU. How would I need to hook up the battery?

As soon as you plug in consumer electronic device made today into the wall socket, the standby power supply is autmoatically on.

The positive terminal of the battery goes to the BL_ON pin and the negative terminal of the battery goes to cold side ground.

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Sorry for my ignorance and all the questions. I really am trying to learn and figure out what I can on my own but I'm still not sure what to do.

Am I looking for something actually labeled "BL_ON", because I do not see it. Two of the pins on the PSU output are "DIM" and "ON/OFF"; could it be either one of those?

[tom66]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Yes, this TV uses ON/OFF instead of BL_ON. You can ignore DIM for now or connect it to ON/OFF, but either way the screen glow should be visible.

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

The backlight does indeed come on.

BTW thank you (everyone) for your help so far.

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Hey so am I supposed to be able to get a reading on all the voltage regulators when it's in standby? Could one of them having failed be the reason I'm not getting a reading on the others?

Also can I be reasonably certain that the power supply is not the cause of the problem? Replacement main boards for this unit are not terribly expensive, but if I'd like to fix it if I can.

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

So if there are no more suggestions I guess I'll be ordering a replacement board...

[PohTayToez]

Re: Insignia NS-LCD15-09 -- Won't Turn On

Replacement main board did the trick