Beginner trying to fix LCD

[johnyzee]

Our LCD tv stopped working. It was giving a humming/buzzing sound for a couple of weeks, sometimes blacking out the screen (at which point the buzzing noise would stop, but sound in speakers still playing). Now the screen is totally black, still a faint buzzing sound.

From what I've read this indicates a failure of the inverter board. So I have taken the thing apart and I think I have managed to locate the inverter board (see attached image). I have looked it over for anything obvious, the only thing I notice is a burnt looking area at one of the capacitor pins (see image).

I was hoping someone here could give a look and let me know if (a) I am correct in assuming this probably a problem with the inverter board, and (b) if the capacitor shown looks faulty to you? I know from browsing that a capacitor can be bad even without visible signs, but I will only proceed if I am sure that I have located the (or at least one) obvious problem.

The TV is a four year old Philips 9632D (42"). I got most of my inspiration from this thread describing a similar problem (same model TV, same inverter board): https://www.badcaps.net/forum/showthread.php?t=14128.

Thanks in advance for any pointers!

[johnyzee]

Re: Beginner trying to fix LCD

Just to get ahead of myself a little bit, if the capacitor is indeed bad, can that in itself cause the buzzing sound I've been hearing, or does that indicate an additional problem? It would surprise me that such a small part would make that much noise, and also it sounded more to me like the sound was coming from the power supply board but I may be imagining things?

Can I replace that capacitor with a simple soldering iron and some tin (never soldered anything in my life)? Is the capacitor a widely available part or would it need ordering? I have a well stocked electronics boutique near here. Also, will the part itself be enough to get the replacement, or do I need a schematic to determine which part to get?

[retiredcaps]

Re: Beginner trying to fix LCD

1) If you have a multimeter, check the fuse on the inverter board (right underneath your green circle). A good fuse should measure less than 1.0 ohms.

2) The brown stuff on the cap looks like leftover flux residue from the soldering process. You can verify by trying to remove the flux with a q-tip and some isopropyl alcohol.

3) When the screen goes black, does the power indicator LED stay green?

[johnyzee]

Re: Beginner trying to fix LCD

1: I don't have a multimeter (don't even have a soldering iron yet). Is the fuse the white thing with metal at each end that says (...)12A? As you can tell I am starting from zero, so I am praying for something blindingly obvious that even I can deal with .

2: Will try, you're probably right. On closer inspection the other pins have a little bit of residue too.

3: The light stays green (blue actually).

[retiredcaps]

Re: Beginner trying to fix LCD

Is the fuse the white thing with metal at each end that says (...)12A?

Yes.

[johnyzee]

Re: Beginner trying to fix LCD

I attached a picture of the power supply board, and a picture of the entire backside for reference - the inverter board came off at the very right by the metal next to the TV.

I don't see any obvious problems on the power supply board.

Do you think it would be worth trying to fix the thing (taking into account my limited experience with electronics repair)? Is replacing one or both of these boards likely to fix the problem in your opinion, or are there other easy steps I can take to troubleshoot further?

I would hate to throw away a fine TV if a couple of cheap parts would fix it right up.