Looking for advice/tips.
a few weeks ago an old man gave me a 60 inch plasma tv for free because he was throwing it away due to the screen shutting off after 20 minutes of use. I opened it up today, plugged it in and could hear a humming/buzzing noise coming from the item circled in the picture.
I dont have an electrical tester, but i do have a soldering iron, the only repair ive ever done was change some capacitors in my other tv. the parts for this tv range from 30 dollars to 200 dollars and all seem to be used. any repair thoughts before ordering replacement Y-Board from overseas?
Samsung Plasma 60'' PN59D530A3F
>>962182
just attach some fans to it. its overheating. the transformer is meant to buzz. its how they work.
>>962182
The circled item is a transformer, if it is broken you are out of luck because those are almost always custom order parts for that particular television/powersupply. Transformers should NOT normally buzz since they are operating at way higher frequencies (25khz - 1mhz), the buzzing is an harmonic effect that can have multiple causes. One cause is that the two core halves forming the transformer (see pic) come loose (they are normally glued together). This can cause buzzing because of the changing magnetic field 'clattering' the halves together. You can easily check if this is the case.
It can also happen when the core is saturated (i.e. the transformer is handeling too much current) and emit sub harmonic frequencies. The same thing can happen when the transformer heats up, because when it heats up the current handling capability drops (both the mean current handeling, and the saturation current drops).
>>962185
>the transformer is meant to buzz. its how they work.
nigga shut the fuck up, you dont know jack shit.
>>962195
This is what i was looking for, it gives me a good starting place on where to direct my research. also from about 15 feet away with the back cover of the TV removed i can hear the humming/buzz.
>>962182
that buzzing is caused by the circuit driving the transformer. its feeding it the wrong waveform. you'll need to check that section first (iow you need a schematic and possibly a scope).
>>962182
go get a dmm
>>962205
search for 'switching transformer buzz' or 'inductor whine'. But still as i said before it is quite tricky, the whine can just be a symptom of an underlying problem.
>>962211
ill go get a meter tomorrow and start poking around, if the thread is still around ill keep you updated, thanks again!
>>962195
>Transformers don't buzz or hum in normal operation.
Go fuck yourself.
t. Electrician
>>962215
If you seriously think they buzz or hum in normal operation, than you are indeed an electrician and not an electrical engineer. Only cheap chinese power supplies buzz when unloaded, you dont know what you are talking about so shut the fuck up.
also
>t. Electrician
why dont you fuck off to whatever board that meme came from, this is one of the few boards that isnt entirely shit up by 12 year olds and actually helpful in most cases.
>>962195
>television works fine for 20 minutes at a time
>transformer is malfunctioning.
nope. doesnt work like that.
>>962221
>hurr i'm an engineer
somebody has never left their moms basement to see substation.
>>962240
>nope. doesnt work like that.
Except that it does, read a book. Also, i never said it could ONLY be the transformer, see
>>962211
"the whine can just be a symptom of an underlying problem."
>somebody has never left their moms basement to see substation.
What the fuck are you on man? Substations? Who gives a flying fuck, this is consumer electronics, not power electrician work. Substation transformers are not even close to the same thing as switchmode flyback transformers.
You seem to be massively jealous of engineers, a typical fox and the grapes story.
You really do not know what you are talking about. Now please stop embarrassing yourself.
>>962240
>somebody has never left their moms basement to see substation.
Please dont change /diy/
Both anon saying transformer buzz or not are right.
It all depends on the frequency it operate.
Typical power transformer at 50/60Hz do buzz in operation.
OTOH, typical switching transformer operating at higher frequency (40kHz, 125kHz, etc) work silent.
>>962246
>OTOH, typical switching transformer operating at higher frequency (40kHz, 125kHz, etc) work silent.
There is no 50/60hz transformer in any semi-mordern television. There are two places for transformers in the television, one in a flyback circuit for a high voltage part (which i think this is, since it is a plasma TV), and in the powersupply. Both operate far above 20khz.
>>962246
>what is harmonics
maybe I am autistic and have super human latent inhibition abilities.
they always make a sound. the assumption is that a transformers input or output can't be switched. which they certainly are. you're never going to be operating at the ideal load of a transformer. deviations from this point are going to introduce harmonics. so IRL, they all hum.
>In general, switched mode power supplies do not generate
>audible noise when they operate at constant ultrasonic
>frequencies (>20kHz). However, some switched mode
>power supplies can produce audible noise at certain load
>conditions. Most Fairchild Power Switches are designed to
>enter into burst switching operation at light load conditions
>to reduce standby consumption, which can cause audible
>noise when the fundamental frequency of the burst switching
>bundles is in the range of human hearing as shown
>This application note explains the major sources of audible
>noise and offers useful tips to engineers to solve the audible
>noise problem in their Fairchild Power Switch (FPS)
>applications.
https://www.fairchildsemi.com/application-notes/AN/AN-4148.pdf
>>962252
You are assuming that the SM controller is indeed capable of doing burst switching, which most are not.
Read the last sentence
>This application note explains the major sources of audible noise and offers useful tips to engineers to solve the audible noise problem in their Fairchild Power Switch (FPS) applications.
This implies that if well engineered, FPS applications should also not be noisy. The whole application note shows how to make it not produce noise, or at least reduce it severly.
Also, OP noted that it was making humming noise during normal operation, not in any low current burst switching operation.
>>962255
somebody can't handle the idea of a system that is not 100% efficient or basic orders of harmonic resonance.
>>962182
forgot to answer OP.
OP it's the FETs on the nearby heatsinks. plasmas get fucking hot. you gotta replace the FETs and the nearby capacitors that they fry when they overheat and bug. it is a common problem with plasmas. especially since retarded cabinetmakers like to cleanly seal televisions in cabinets. exhibit 1: a faggotty cabinet. seals in the heat to keep everything nice and toasty. these were all the rage while CRTs were around and stuck around until wall mounts caught on.
>people still install shelving directly above their wall mounted televisions for secret cabinetmaker conspiracy reasons.
I died a little every lecture at university when my IT professors couldnt understand why the clients kept freezing halfway through the lecture.
>computers sealed in unventilated cabinets
>>962258
>somebody can't handle the idea of a system that is not 100% efficient or basic orders of harmonic resonance.
What are you on about? A well designed switching psu should not hum with normal operation. You failed to explain WHY the switching PSU would produce those harmonics, because if it is not in some kind of burst switching mode, or resonating mechanically (which is what i already mentioned, and it is a fault condition because there should not be mechanical movement between coils, wires and core halves), it should not resonate lower than the switching frequency. If you did learn your electronics right, you'd know that harmonics exist only above the fundamental tone, which is the switching frequency if there is no burst switching. You have not ONCE denounced my claims with facts or reasoning, only with insults, yet you claim you already have the fault without any debugging or probing, just because it happens with plasmas sometimes. I sincerely doubt that you do in fact have an engineering degree of any shape or form at all, because you are not approaching this problem in a scientific manner, or arguing like a decent human being at all.
>>962263
>thinks his 1st year engineering knowledge compares to trade knowledge in a field he has never worked in
there is a reason tradies get buttmad when an engineer walks into the machine shop.
degrees mean shit these days anyway. doctors literally go to wikipedia infront of patients and look to oprah for the source of their professional development training.
a TV shutting down after operating for 20 minutes is deffinitely a thermal shutdown protection system. which is caused by overheating FETs.
>>962266
>assumes i am a 1st year engineering student
>assumes that this is a field i have never worked in
the reason why tradies get buttmad is that they are jelous as fuck because they dont make nearly the same amount of money, in not nearly the same comfortable conditions, whilst thinking they are superior and doing a better job or something.
And if you really think degrees mean shit, why dont you get one? You'd earn a lot more money with it.
You cannot design a switch mode power supply, i can because i do have a degree and do know how to do that shit. Good luck designing one without a degree, because you dont even know jack shit about the mathematics involved.
Same is true for doctors. You can google symptoms, but you have no actual knowledge of the disease itself to clearly identify what it is, and how to treat it.
Degrees are for specialists in specialist fields doing work that has incredible amounts of responsibility, because if something goes wrong, it is not just one TV that breaks, but a complete series, which costs a lot more money, or a person that dies.
>pic related, literally you
>>962266
>a TV shutting down after operating for 20 minutes is deffinitely a thermal shutdown protection system. which is caused by overheating FETs.
Does not have to be a thermal protection issue at all, can be anything thermal related. Also, i have had equipment shutdown because the powersupply was unstable during certain load conditions, nothing to do with thermal issues at all (although i do agree that thermal issues in general are the most likely culprit, but that can still involve the transformer and its significant drop in saturation current capability).The only way to know is to start probing around and doing tests. Not willy nilly replacing parts until you by chance get the correct one. The former is both cheaper, quicker and more professional.
>>962221
>cheap Chinese
Which is exactly what every fucking transformer that is PCB mountable is you dildo. You think there's an American, german or Japanese transformer in that cheap American product? You're insane.
>>962451
Cheap chinese, as in referring to cheap chinese components and most of all cheap chinese design with lots of corner cutting.
There is nothing wrong with chinese components or chinese design persé, it is merely a term used to describe the cheaply produced goods that try to save cents on everything, think of those 1$ phone chargers for example. It has nothing to do with the actual country of origin. You seem to be the dildo if you did not know that.
No big brand name would try to ruin their reputation by using those power supplies in their televisions.
>>962456
Also forgot to add, that is most likely a flyback transformer for the high voltage part, so there is pretty much 0 chance of that powersupply being ordered from a secondary supplier, thus being designed in house.
>>962451
You also seem to be retarded if you think all transformers mounted on PCBs are chinese.
Here are just a few non-chinese companies producing top quality transformers specifically for switching powersupplies. Stop talking about shit if you dont know what you are talking about.
http://en.tdk.eu/
http://www.sumida.com/
http://www.we-online.com/web/en/passive_components_custom_magnetics/welcome_pbcm/Welcome.php
http://www.pulseelectronics.com/
http://www.cooperindustries.com/content/public/en/bussmann.html
http://www.vishay.com/company/brands/sfernice/
>>962221
>>962270
I contract to Suncor. I made more last year then you will in the next 5. I've put together 20,000 sqft MCCs. I've don't power Distro from ground up on BULLION dollar operations.
Yeah. After PQA and TVA a system running at 99.8 still hums. Hmmmm must be fucked I'm going to listen to this A1 goof engineer 1st year liberal fag who should stick to Copy pasting design prints and soldering threads.
I'm going to fly home on Friday, collect a 7 day cheque that's more than you make in 2 mos and fuck this while you fuck your flashlight in your mom's closet.
TL; DR this kids a homo. Transformers hum.
>>962469
PS should I add now that I'm
t. BaSC Electrical Engineering from UBC?
Does that make you feel more like an idiot?
Go fuck yourself right off this board. Please.
>>962456
>w-well Chinese doesn't always mean Chinese
Grasping, desperately grasping.
>>962469
>picture of douche on the fridge, probably you
>old outdated appliances owned by a person that makes well into 6 figures by his math
>a rear picture of a friend who uses you for your pool and money
>>962494
It's her house.
I give her nothing.
Great detective work.
>>962496
Using women now too? Real scumbag you are.
>>962469
>>962480
>implying you know how much i am making
>implying you would even be contracted if you can even spell correctly " I've don't power Distro from ground up on BULLION dollar operations." almost sounds like copy pasta
>implying you have an engineering degree
>implying high frequency transformers hum
>implying what you are claiming over the internet is true at all
you are a meathead that could not even pass the bachelor of electrical engineering, there is no shame in admitting that. You dont even know that there is a difference between high frequency switching or power station transformers.
I gave multiple arguments why exactly what you said is false, yet you retort with 'but muh power transformers, you are 1st year bachelor, you are homo, muh paycheck' instead of actual factual arguments demonstrating that you are right. In short, you dont know jack shit about real electronics inside devices yet you pretend you do, you even use the 'muh power transformer' argument even though this is a thread about a fucking television high voltage transformer. Also, there is no way you'd get this defensive if you actually had a degree. You are most certainly the fox that cannot attain the illustrious grape called 'a university degree'.
tl;dr; you have a nice imagination pretending that you have all those things, but it is time to return to the board where you came from, because not once have you been helpful mr.fox.
>>>/b/
>>>/trash/
>>962493
>ignoring all the actual facts in the post
>now i've got him
nice job shifting goalposts after having been proven wrong you faggot
I guess one of them is bork. Check them as well.
>>962680
ahem.
so what pitch is the hum, relatively? 60Hz, higher?
So I'm not a real engineer or anything, just a hobbyist who needs to repair the odd synth every now and then. I was replacing the screen on one synthesizer, and ever since then, the transformer in the PSU emits a hum somewhere in the 10khz range. Pretty annoying for it being an instrument, but oh well, it works.
tl;dr even an idiot hobbyist knows that transformers hum
>>962710
As a musician, I'm not too picky about the words I use to describe the tone of transformer hum, so idk why you're nitpicky about that. If I call a 10khz tone a hum, don't be the autistic fag who needs to correct me on what the tone sounds like.
>>962716
>>962704
trust me, it should NOT hum when properly designed. If you buy that screen in the shop, it surely will not have that hum.
It is however, common that the lemination between winding can come a bit loose, producing that hum without any significant side effects. But still, that is not what it is supposed to sound like.
>>962195
>>the transformer is meant to buzz. its how they work.
>nigga shut the fuck up, you dont know jack shit.
Thanks for starting a fucking 12 year old scream-fight. You're whats wrong with this board.
>>962716
>musician
>can't describe a timbre
>>963673
I disagree, he tried to help with his knowledge, what is wrong with this board is people that do now actually know what they are doing trying to help.
Although he could have used some nicer words.
>>962182
if you dont even know what that in your picture is then why you even bothering to repair it ??
>>962221
You're wrong. Just stop and move on.
>>962251
Switching power supplies scream at 15khz
>>962270
Yawn, enjoy waiting 10 years after you start school to crack 6 figures on average. As a tradesman you're likely to do it in 5 and not have student loans to deal with. Enjoy feeling intimidated and knowing you're down on loot around tradesmen.
>>965552
Nice arguments to proof why i am wrong
>>965553
You bring a lot of proof with you to make your point, you must be right.
If you did not notice already, the above is sarcasm.
>>965556
Wow again, you say so so it must be true. Why doesnt everybody quit uni to become a tradesman because they earn tons more even though they know less! Btw if you didnt know, in most civilized countries it is possible to do uni without any loans at all.
All in all, you really seem to crave the grapes again mr. fox.
Also see >>963751
>Also it doesnt really matter. OP got what he wanted a long time ago >>962213 Now please let this thread die to make room for proper threads.
