I am attempting to repair a TV (Insignia ns-32e570a11). Considering the symptoms (power light stays on, screen flashes, no picture) I am suspecting the power inverter is at fault.

Unfortunately, it appears that the power inverter and power supply are on board on this model (DPS-120RP-1 a). As a result, I am finding it difficult to figure out whether the problem is in fact with the "power inverter" or if it is actually something else, such as the main board.

Any suggestions? I tried tracking down a schematic for the board, but none is available (company won't release information either).

 

I can get it going, only if you post good pictures showing both sides of the board and all.

 

came across this site, maybe it could help...

http://www.fixya.com/support/t13012305-insignia_ns_32e570a11_no_picture_or

 

Thank you for the posts and I apologize for the delay in responding. I had assumed that I would get emailed when someone posted a reply - I suppose that I will need to check my account setting and make sure that I keep on top of that.

As for the board, I am still struggling with it. I decided to take a shotgun approach and replace every electrolytic cap with exception of the two largest caps. This has not helped.

Currently, I am removing the transistors and attempting to test them. My first attempt is leading nowhere however; as I cannot find a datasheet on the transistor and as such I don't know how to test it. AM image is provided, here are the details for clarification:

- top left corner has marking "O"
- top right corner has marking "13"
- center has marking "J"
- center has marking "SP952
- center has marking B30H60G
- bottom left has marking "ON"
- bottom right has marking "AKA"

Currently I am just trying to test every component on the board in hopes of finding something useful. Unfortunately, I do not know any better way to approach the board as a whole given that I am failing to reverse engineer it.

 

http://pdf1.alldatasheet.com/datasheet-pdf/view/426375/ONSEMI/MBRB30H60CT-1G.html

The Fullpak version. A simple diode test will reveal if it's still intact.

This will take very long if you try to test every semiconductor....

No way to identify at least some of the signals on the connectors? Power supply, input output, signal lines...?

 

Thank you very much for the datasheet, praondevou. I did a simple diode test and this component looks good.

This is my first full-blown PCB repair, so I apologize for likely missing something. I have tested the 5v out and that is steady. When I power on the PS, the 12v out looks good as well.

What I have not figured out yet is how to test the signals going out to the lights (the various CCn outs). Without a schematic, I simply don't know what is good/bad here. What I do know is that I consistently get a quick flash each time I power on. Also, one time I accidentally shorted something on the PS and to my surprise, the TV lit up and worked great for about 3 minutes - I even saw the menu. I tried reproducing this accident, but to no avail.

Any suggestions on how I could narrow my search would be appreciated. I started trying to write up a schematic working backwards from the CCn outputs, but that's a bit out of my league at the moment.

 

Have you inspected the boards for bad solder joints? Some might only be visible with a magnifying glass. Look for very small cracks.

Is this your TV? How did the problem start? Did it not very work anymore overnight or did it start failing occasionnally?