Hello /diy/, I'm here for advice.
My old-ish TV (Sony KDL 40W-2000) has been making some buzzing sounds from behind lately, so I decided to remove the rear cover to have a look and give a good clean while I was there.
I was hoping to find something obviously wrong, but of course everything looks fine to my uneducated eye, it wasn't even that dirty despite being years since the last time dust was removed.
I'm at a loss now, the TV works perfectly fine, but that barely audible buzzing sounds means something is wrong and it will get worse sooner or later.
Pic is the whole thing, details in the next posts.
I don't know why, but 4chan is not allowing me to post images, sorry for the delay.
Here is the part where the buzzing noise comes from, I am assuming this is some kind of motherboard.
Anyway, I can't pinpoint the exact origin of the noise, but it seems to come from the lower half.
I was expecting some loose connectors or balls of dust clogging something, but everything looks fine and I'm not too much into electronics to identify all the things I'm seeing.
If you guys need additional pics or details, just ask.
I just want to understand if this looks like something fixable by myself or if there is some kind of additional test to identify the malfunctioning part.
On an unrelated note, I was looking at this metal bar with 10 slots in there. I have no idea what are those white things inside each slot and they are all covered by transparent plastic film.
Some of them have what looks like burning marks on the film though, what are they? How would I know if something is wrong in there too?
Keep in mind the TV has been repaired by Sony shortly after purchasing because of burned pixels and uneven patches of colours on the screen, so those marks may be leftover from the previous repair.
Any help? Should I just bring it to a professional or wait for an actual problem to arise?
What can I do to understand where the noise comes from and see if it is an easy fix?
It's probably an electrical buzz, not much you can do about it.
>>917201
Yeah that's exactly an electrical buzz.
It is not causing problems now, but I'm worried about it getting worse or being a fire hazard.
Any idea what those white things with the burn marks are?
>>917203
The noise seems to be coming from the middle of the lower part of the board, between the two heatsinks and under those two round things which I'm assuming are capacitors. I can't get any more precise than that unfortunately.
Anyway, I guess there is not much I can do about it
>LCD column driver?
I'm going to trust you on this, because I have absolutely no idea.
>>917204
https://en.wikipedia.org/wiki/Mains_hum
Likely to be the transformer causing the buzz/humming. Nothing to be too concerned about.
The 'burn' marks on the column drivers could be the plastic ageing.
>>917190
I think these are the transformers and connectors for all the backlight tubes. (This is an older TV so it's a CCFL backlight.) I don't see any burn marks in the photo though.
Do any of the capacitors on the power supply board look like they are leaking or have bulging tops?
>>917207
It doesn't sound like your traditional electrical hum, it is very low, but it sounds like when you have a power supply cord partially out of its plug or you keep a light switch halfway between the on and off position and it makes those "discharging" sounds.
It's a cracking sound, it is what I would associate at sparks. I can't see anything wrong though and the noise is so low that I can't even tell exactly where it comes from.
It is not what you linked me to anyway.
>>917210
You can see the burn marks here, it's that black shade that looks like a reflection on the clear plastic.
And no, nothing looks like it's leaking, bulging or burning as far as I can see.
>>917223
Something might be arcing then. Maybe there's a broken winding in one of the transformers or a cracked solder joint.
>>917229
How would I tell? Shouldn't the TV be showing some signs of malfunction?
Anyway, I dusted everything and put the cover back on, unfortunately it looks like the problem is beyond my skills and tools.
I just hope it won't set fire to something one day.
Thanks for the tips, everyone.
>>917202
High voltage transformers to feed the panel.
Even though it has a burn mark I'm sure it's ok because the tv still works.
>>917256
Sometimes buzzing noises can be caused by inductors (the coil looking things) or transformers vibrating slightly (or at very high frequency). Often they'll be glued down with what looks like hot glue gun glue to minimize it at the factory, or be glued internally. Over time, as thing get hot and cycle, they'll shake themselves loose. If you can isolate to a single part, slap some hot glue on there and see if it helps. Full disclosure: I have no idea what I'm talking about.
