40" RCA L40FHD41 No Picture + No Audio

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Front and back

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

i would touch up the solder on the cap above rs9, could ark over on that cap.

[dskall]

Re: 40" RCA L40FHD41 No Picture + No Audio

Since you now seem to have a short. I would look at each of your new solder connections for solder bridges.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

When i was desoldering the original cap above rs9 my iron was too hot and removed the copper plating on that part of the board.

I tried scraping the board to reveal more copper underneath (saw on internet) so i could have something to solder to but made a hole there.

I tried to bridge that solder joint to what looks like a tiny transitor (followed the circuit path) - is that right?

It didn't work so i desoldered that bridge and tried to solder the cap regularly while missing the copper plating on one of the joints...

Any idea on what i can do about that ?

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

soldering to the next component is fine.

it just looks like there is too much solder. i would remove it, bend the legs out slightly and resolder. while your at it, j12 looks to have a bad solder joint on it.

after that is done, it will be time to look at the output voltages that go to the main board.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Ok so i must have removed the short because the ticking sound coming from the power board has stopped, tv screen will turn on but still shuts off

Left side is black, right side is red now (not blue like originally)

I think by transistor i meant resistor...

On to measurements?

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Update:

I have since cleaned all cables on the back of the TV, now i have audio from the TV,

there's a button on the main board that seems to reset the board and resets tv to HDMI 1 (possibly by default) - laptop connected = audio!

When i first power on TV, it shows me yellow and red bars with left half of screen black, then syncs to input from laptop, plays audio and fortunately still i can see picture if i hold up flashlight to tv.

Between those red and yellow bars, half of the screen being black and then shutting off (the screen isn't really shut off) - it seems as though the backlights aren't working maybe?

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Update #2:

I wanted to show you guys the work I did on one of the capacitors, the one above rs9 and how i have it soldered to the next component (resistor ?) - is this okay?

I know its utter shitty work, it was my first one i did and the rest came out better, i messed stuff up and this was/is my improvised workaround.

(solder flux shite everywhere)

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

I would have bend the lead over to that large unused pad instead. I cannot tell how good the solder works i to the end of that SMD cap in the picture.
BTW, why the solders works look so dark instead of shiny? Even the leg of the cap looks dark.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

I really don't know why it's so crappy looking, i lowered the heat on my iron, maybe it's too hot still?

Flux residue resides alot, i tried cleaning with alcohol and small brushes

I will remove that solder and try the pad instead

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

bud, i removed the solder joints pointed out and soldered to the pad instead

yellow bars are gone, half of screen still red though, audio still works

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

I seem to remember when i first got the TV i could plug it into the wall and the TV would wait for you to press power to power it on...

Since i've changed all the capacitors, as soon as i plug into the wall outlet, the TV powers on...?

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

since there was some initial pad damage i would check for continuity between the pins on those pads, just to make sure.

you said that you are getting a flash of picture. any chance of a pic. while it is plugged into the laptop, are you getting audio but no pic, or is the pic showing up?

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Continuity between the pins on what pad?

I'm not getting any picture per say, rather, when the TV powers on half of the screen is backlit and red, the other side is black. This lasts for a second or two until the whole screen goes dark.

With the laptop being hooked up i am getting exact same results, except i am getting audio from TV (HDMI via laptop)

No picture, but audio exists

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

since there was some initial pad damage i would check for continuity between the pins on those pads, just to make sure.

Here is what it looks like now before and after with the capacitor now soldered to the pad to the right; I did remove the solder connection from the SMD chip beneath and now instead am soldered to that pad that Budm mentioned above

Where should i check continuity?

[attainteddragon]

Re: 40" RCA L40FHD41 No Picture + No Audio

that looks heaps better.

just check across the cap. if there was any stray trace, it would show low ohms.

on the ps, the connector that goes to the main board, we need to know the voltage on each pin in standbyand when powered on. use the chassis for ground.

eg.
pin no, pcb marking, stby v, power,on v.
1 12v 0.00v 11.90v
2 ps on 0.09v 4.96v
etc.

it has 2 rows of pins, so you will need to test it where the cable goes into the connector.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Ok, beginner questions:

Does power cord need to be plugged in/TV switched on for testing the capacitor?

How about testing the connector?

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

Can we see the screen shot of what you are seeing on the screen? At this point I do not believe you are having power supply problem since the backlights are on and based on what you describe what you are seeing on the screen.

[ajsterr4]

Re: 40" RCA L40FHD41 No Picture + No Audio

Can we see the screen shot of what you are seeing on the screen? At this point I do not believe you are having power supply problem since the backlights are on and based on what you describe what you are seeing on the screen.

TV powers on and shows this for 1 second

edit

The black on the left side is not an error in the photo, the left side of the screen is faded black as such BUT when i connect HDMI to it and hold a flashlight to the (dark) screen, i can see the whole image is being shown throughout the entire screen.

[budm]

Re: 40" RCA L40FHD41 No Picture + No Audio

OK, so backlights do not stay on.