Insignia 37 inch LCD, has sound, but no video. What to do?

[Umortal377]

Got a 37 inch Insiginia, model NS-LCD37. Wife called me the other day and said the tv wasn't working. After checking it out, it seemed the sound was working, but no video. The TV comes on normal looking for a second or 2, then kicks out to darkness.

I did notice however in a completely dark room, I can make out outlines or very faint images on the screen.

I opened it up and took pictures to post, but realized I didn't bring the cable with me to hook it up, so I cannot post any pics till tomorrow.

I didn't see anything that stood out as bad. However, I didn't take everything off. But did look around some.

My soldering skills are ok, not the greatest. But I have replaced a couple transistors and chips on some crane machines and arcade games I use to collect. So I know enough to probably hurt myself, lol

[smalltownguy]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

The famous "2 seconds to black" behavior. You have a fault in the backlight circuit. Either a bad inverter board or bad CCFL tubes. More likely the inverter.

Bad capacitors in the inverter circuit will cause this. We've already established that you don't have the capability to test any of the caps, so shotgunning the inverter board is probably your best bet.

Get some good quality pictures up so we can see what you've got and we'll go from there.

-STG

[Umortal377]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Thanks, I will try and get my pics on here tomorrow morning. Think I found some replacement boards online, but want to check the TV to make sure the parts are the same.

I still wouldnt mind trying to fix this board. I have a soldering gun and a multimeter. But we recently moved, so I have no clue where they are at. Gonna look for them tonight.

[budm]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Yes, do post the pictures and do some voltages checking first before start buying boards. You may want to read this also.

[retiredcaps]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

We've already established that you don't have the capability to test any of the caps, so shotgunning the inverter board is probably your best bet.

The shotgun approach is contrary to philosophy and skills of most of the regular members here.

[Umortal377]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

I tried to load the pics this morning, but I got an error saying:

Your submission could not be processed because a security token was missing

[Umortal377]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Looking at all the boards I could see, I dont see any damage.

I did pull the inverter board all the way out. Looking online, I couldnt find an exact match on the part #. The part # is VK8A183I0207. Looking online, I can find something close, but not exact. I found a VK8A183I07.

[Umortal377]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

The shotgun approach is contrary to philosophy and skills of most of the regular members here.

I still plan on trying to fix the board. But I want to get the TV up and running, then tinker with working on the old board in my spare time. Still havent found my multimeter or soldering setup.

[selldoor]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

I tried to load the pics this morning, but I got an error saying:

Your submission could not be processed because a security token was missing

Hi - nothing to do with a security token - your pics are just too big they need to be under 2mb 2000x2000 - you will need to downsize them a bit.

[Umortal377]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Here are some pics

[selldoor]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

I would test the secondary windings on each inverter transformer
No power to the board meter on 2000 ohms when you find it check
as per pic S1>S2 and S3> S4 No need to remove to check.
Post results as follows
T1 S1>S2 = xxx ohms S3>S4 = xxx ohms

T2 S1>S2 = xxx ohms and so on.



SORRY - Set meter on 20,000 ohms these should be just over 2000

[selldoor]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Actually I cant make out all the part numbers on the transformers but they dont all look the same which is a bit odd perhaps you can list them I thought I saw 6007 and 6004
Its the first 5 digits that are important.

[budm]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

F1, F2, F3 are good? This board looks like one of those DARFON with bad transformers.

[selldoor]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

F1, F2, F3 are good? .

Old Yesterday, 06:51 AM #1
Umortal377
New Member

The TV comes on normal looking for a second or 2, then kicks out to darkness.

I did notice however in a completely dark room, I can make out outlines or very faint images on the screen.

I think that covers most fuses?

[budm]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

If one of the fuse on the inverter is open, you will see backlights on and then goes into shutdown since the PWM IC of the inverter will detect that not all the lamps fire up. It is also why when you have open winding on the secondary side of the inverter transfomer, the inverter will go into shutdown due to lamp did not fire up, the widows on most circuits is about 1.5 second of detection time, anything does not happen after 1.5 seconds, it goes into shutdown during the lamp fire up and stays conducts sequence. Hence you are seeing these 2 seconds shutdown.
Just to be sure.

[retiredcaps]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

If one of the fuse on the inverter is open, you will see backlights on and then goes into shutdown since the PWM IC of the inverter will detect that not all the lamps fire up.

Yup, there is a documented case study that I highlighted in my 2 seconds troubleshooting guide the above scenario.

https://www.badcaps.net/forum/showthread.php?p=197027

[Umortal377]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Just a followup, after replacing the inverter board, the TV now works.

[selldoor]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

The good transformers off the old one will be saleable as I recall they are about 20$ each so probably worth the effort removing and testing.

[Daddyfixit]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Hi all I have to thank you all for sharing what you do, but I'm having a problem with my Insignia NS-LCD37 also. Having said this, everyone talks about the red light on then going to green, but mine goes to blue, and I see nothing but black? I have read as much as I could about similar models but, I'm not sure where I stand in comparison to others with similar models.
The TV worked great for over five years but now no longer powers up, I only have that red light stating that I'm plugged in and when I hit the power I don't see anything but the blue light on and no sound. I have it apart but I definitely don't know where any main fuses are or know exactly how to check the transformers. All my caps look super clean and I went as far as I could testing my main ac board. The values didn't all match so I condemned that board, ordered it, installed it and no luck. Transformers are what I'm assuming but the ohm test you've posted to test doesn't match what I read, but still not sure as to which direction I need to go in my case. Any help will keep my daughter and wife's faith in the daddy can fix it phrase alive . Please advise

[budm]

Re: Insignia 37 inch LCD, has sound, but no video. What to do?

Please go back to this thread or stick to this one so we do not have to try to follow 2 threads, thanks.
https://www.badcaps.net/forum/showth...110#post349110