Replacing a bad cap on TV

[justjoe]

Re: Replacing a bad cap on TV

Can we get a close up of this sticker too? We can perhaps look up the panel datasheet from it.

OK thanks I will do that, ive just soldered the cap back on and the picture is fading in quickly then fading our slowly and does that every 5 or 10 seconds, same symptoms basically so its not the cap.

I will go take those pics.

[justjoe]

Re: Replacing a bad cap on TV

can we get a close up of this sticker too? We can perhaps look up the panel datasheet from it.

[justjoe]

Re: Replacing a bad cap on TV

Red probe on the exposed metal around each pin leaving the power supply.

Do you mean these pins?

[tom66]

Re: Replacing a bad cap on TV

No. The main board has video inputs like HDMI, scart on it.

You want to follow the connectors from the main board, any one which goes to the power supply you need to test.

The TV should be powered on.

[justjoe]

Re: Replacing a bad cap on TV

No. The main board has video inputs like HDMI, scart on it.

You want to follow the connectors from the main board, any one which goes to the power supply you need to test.

The TV should be powered on.

ok i will go give that a try thanks, do i need the datasheet to find out what the correct readings should be?

[justjoe]

Re: Replacing a bad cap on TV

I think I found the datasheet

http://www.panelook.com/V390HJ1-L02_...ter_15149.html

[tom66]

Re: Replacing a bad cap on TV

The datasheet is not currently necessary, however, it may prove useful later.

[justjoe]

Re: Replacing a bad cap on TV

The datasheet is not currently necessary, however, it may prove useful later.

ok heres the voltages...

[tom66]

Re: Replacing a bad cap on TV

Did you test with the connectors in place? This must be done to provide a "load" to the board. If you did so the power supply would appear to be good.

The next stop is to look at the main board. Do you see that long thin black cable going from the main board to the top of the LCD screen? Can you get a picture around the connector for it on the main board?

[justjoe]

Re: Replacing a bad cap on TV

Did you test with the connectors in place? This must be done to provide a "load" to the board. If you did so the power supply would appear to be good.

The next stop is to look at the main board. Do you see that long thin black cable going from the main board to the top of the LCD screen? Can you get a picture around the connector for it on the main board?

Yes they were connected and tv powered up.

Heres the pic...

[tom66]

Re: Replacing a bad cap on TV

Good, thanks. Can you check the voltage on the top left pin of that connector with and without the cable installed?

[justjoe]

Re: Replacing a bad cap on TV

Good, thanks. Can you check the voltage on the top left pin of that connector with and without the cable installed?

ok its reading 12.84v both connected and disconnected.

Do you think this is looking like a new mobo replacement? because its hard to find one and i guess they are expensive.

[tom66]

Re: Replacing a bad cap on TV

That's good, then.

It's looking like a panel problem to me.

One more thing to confirm: Can you upload a video of the problem? I'm struggling to imagine it well enough.

[justjoe]

Re: Replacing a bad cap on TV

That's good, then.

It's looking like a panel problem to me.

One more thing to confirm: Can you upload a video of the problem? I'm struggling to imagine it well enough.

I thought of that but the only time i get any kind of picture is when i leave it unplugged for days, but even then its mostly just a black screen, but with working backlight.

when you say panel do you mean expensive? lol

[tom66]

Re: Replacing a bad cap on TV

LCD panel is not economical to replace (80~150% price of TV), and the fading effect you describe is common on some LCD panel failures.

Sometimes you can apply a tab bond shim. This sometimes works, but not always.

First, please make that video if you can..

[justjoe]

Re: Replacing a bad cap on TV

That's good, then.

It's looking like a panel problem to me.

One more thing to confirm: Can you upload a video of the problem? I'm struggling to imagine it well enough.

This is exactly the same problem i have.

http://www.youtube.com/watch?v=VuKIo_m2n9I

I had this problem with an old pc monitor, i removed the back and pressed down on the components and unplugged things and replaced them and it worked so i was hoping this might be the same.

[tom66]

Re: Replacing a bad cap on TV

That's the backlight. In a dark room, when the screen is "dead" (that is it has powered up and it has faded out) do you see screen glow?

[justjoe]

Re: Replacing a bad cap on TV

That's the backlight. In a dark room, when the screen is "dead" (that is it has powered up and it has faded out) do you see screen glow?

yes the glow is very bright, the screen isnt actually black its blue from the brightness of the backlight.

[tom66]

Re: Replacing a bad cap on TV

So it's probably a panel problem, like this
https://www.youtube.com/watch?v=purk_SyiT44

Different symptoms, probably the same cause.

[justjoe]

Re: Replacing a bad cap on TV

So it's probably a panel problem, like this
https://www.youtube.com/watch?v=purk_SyiT44

Different symptoms, probably the same cause.

well ive tried doing what he did and those ribbons seem to be ok, i dont get anything happening to the screen when i touch them.