40" RCA L40FHD41 No Picture + No Audio

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

Taken from backside of LCD panel

Samsung LTA400HA07.
I will have the search for the spec sheet of this panel.

Inverter board:
Toshiba/RCA/Samsung LJ97-02098B (INV40N14B) Backlight Inverter SSI-400-14A01
http://www.shopjimmy.com/toshiba-rca...t-inverter.htm

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

When checking fuse, you will use the lowest Ohm scale the meter can do, in this case it will be set to 200-Ohm scale.
Please read post 77.

I replied to that post, also. The fuse test I am now getting reading of 00.3 for both fuses , on 200OHM setting

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

The fuses are OK otherwise half the set of the lamps will not light up.
I am leaning toward bad imverter board.

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

BTW, look at the bottom side of the inverter board to see if there is any sign of burnt on the bottom side.
https://www.badcaps.net/forum/showth...=SSI-400-14A01

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

BTW, look at the bottom side of the inverter board to see if there is any sign of burnt on the bottom side.
https://www.badcaps.net/forum/showth...=SSI-400-14A01

Here's a picture of the backside of inverter board, the top looks like it was exposed to some heat

The burn marks lead to the area right where the capacitor on the right is and where that eight legged transitor is (see pictures)

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

The hi-heat discoloration goes down the whole length of the inverter board (backside) but it's not as dark in some places. There are 14 mosfet transitors that run the length of the board too.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

These are the mosfet that are on the board

PDF



I am getting ~0.567k on D1 pin 5

When I check the other Drain pins 6,7,8 I do not get a reading

Negative probe on source, charge up the Gate pin, then red lead to Drain

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

in your pic with the ccfl's on, the 3rd from the bottom is not on. can you confirm/deny if is working or not.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

It's possible it was working at some point or maybe I didn't snap it in all the way. Oddly enough since I've taken that picture, 2 ccfl bulbs broke (one of them being the 3rd from the bottom) it broke trying to snap in/out.

2 bulbs are now missing but the other bulbs still light up and shut down the same. Can you operate the TV with missing bulbs?

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

that's a problem. even if the inverter board was ok, it would sense that pulling different amount of current from each transformer, so it would shut it down to protect itself.

so, you now either need to replace the ccfl's that are broken to continue, or call it a day on this one. if you could get your hands on a broken screen set, that would be awesome.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

A broken screen of the same model or any 40" LCD?

Before taking it apart the lights would still shut off so unless there was one bad bulb all along or I made it worse and the original problem still exists elsewhere.

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

i would aim for the same model, as you may get hold of the same inverter too, though not a guarentee as they could use a few through their build cycle.

unfortunately i can't tell if the ccfl was working prior to now as this is the first pic that i have seen of it under the panel.

there have been cases where ccfl's have come loose from connectors (on other models),
so that may of potentially been a fault as well.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Finding the same model will not be easy.

Can I use certain components from other TVs? Like bulbs or transitors?

Would any 40" suffice for this stuff?

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

as far as the ccfl's go, most of them are 3mm diameter and leaded, but length can vary a bit. a 40" is generally close though.

components can be used in lots of places, even an unrepairable board can give you enough parts to fix many others.

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

It looks like one of the inverter transformer got hot too.