I recently purchased an a500 and I noticed for the first time today that it has a faint high pitched whine coming from the back of the unit, most noticeably from the speaker cutouts. It gets louder when plugged into the charger, but is still extremely faint. The noise is not present when using headphones, and adjusting the brightness or turning off the auto brightness makes no difference. I searched (yes, i searched first, lol) and found some info about screen whine, but nothing specific to the a500. I originally thought maybe the speakers were picking up something, maybe from a bad ground, but the noise is extremely consistent. it never changes pitch and only gets slightly louder when plugged in. My first instict was to exchange it, but I have already done that three times to get one with no dead pixels. The noise is extremely faint, and were it not for my OCD, I probably never would have noticed until I would have tried to watch a movie in a quiet oom while charging. Any thoughts would be appreciated.
screen whine?
- Thread starter BeNT
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I purchased it at Best Buy. The first one had dead pixels so I exchanged it, then had to exchange that one for same reason. When the third one had dead pixels as well, I thought maybe there was a bad batch so I exchanged it at another Best Buy about fifteen miles from here. This unit has, and still is working flawlessly, other than the whine. It is almost impercptible. It does get louder when the charger is plugged in though. You have to hold the tablet speaker to your ear to hear it unless charger is plugged in. I only noticed it because I was in a very quiet room with the charger plugged in. I tried to search to find if this was normal, and some other forums stated that in similiar cases it was the hardware controlling the screen and that meant it was soon to fail. In all of the other cases it was not an Acer tablet, so i figured i would ask here to see if it was normal. If it is not, I would like to be able to exchange it for a new one at the store while I can. I have tried a factory reset hoping it was a bad driver install or something , but it is still there.
P.S. No these are not refurbished units.
P.S. No these are not refurbished units.
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no, the volume control does not affect it, nor does the brightness control. yes, it disappears when sleeping. it is constant and only gets slightly louder when charge cable is connected. pitch, volume, etc. are always the same. i have done a factory reset and there is no change. with normal usage, i doubt the average user would ever notice it. it is so slight that it doesnt bother me even with my ocd. i just dont want this to be a sign of impending failure. i have seen three pr four posts of people with the same issue. all but one were using custom roms though and they stated that reflashing or changing rom fixed it. mine is completely stock and not rooted.
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As you've probably guessed by now, this is NOT common, and probably NOT harmful, and NOT indicative of immanent failure.
If brightness does not affect it, and volume does not affect it, it is most likely the noise is being induced into the speaker wire somewhere past the sound chip (on the way to the speakers).
See the routing of the speaker wire in this photo . The routing of the Speaker wire is probably just a little bit different in yours than others. If you look carefully at that picture you will see the speaker wire (round) running parallel to the screen ribbon cable. A slight mis-positioning of that cable (like out from under one of the clips that hold it in place) is all it would take.
I don't think this is a big deal unless its loud enough that it bothers you, in which case I'd take it back.
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i agree with you on all counts except, i dont think it is induced noise. i think it only appears to be coming from speakers because that is the only opening in the back. i think something else is oscillating. another interesting point is that the buzz stays the same volume when you initally plug charge cord in, but any movement of thr plug causes it to get louder, like a bad ground in the chstging circuit. seeing as best buy is out of stock and with the christmas extended return policy, i have until january 24th, so i think i will wait and see whst happens between now and then. if it stays as it is, i will keep it (unless my ocd kicks in lol)
Hi everyone,
I've noticed that there isn't much technical advice for the hardware in this thread, seeing as I'm an electronics tech, I thought I might share my thoughts.
Given what has been said about the whine, that it doesn't vary with brightness and such, but does stop when the tablet is asleep, I would expect that the sound is coming from the switchmode supplies that regulate the battery supply. The frequency these supplies run at is around the 2 - 20khz range, and is very perceptable. I'm going to guess that one of the inductors is a bit "loose" and the wire coils are able to vibrate at the operating frequency, hence the whine.
I'd doubt that anything will come of it, I wouldn't expect it to cause any problems, but it won't get better, an easy fix would be to pull the thing apart and apply a small dab of glue to the coils, this should fix it up for good, but it's a fair bit of work if the sound doesn't bother you.
I've added a pic or two of what the inductors should look like, if you can't see the copper wire coils on yours, then unfortunately you will be unable to try this fix.
Hope this helps, Mike.
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Mamahnita
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- Nov 27, 2011
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This is the first time I ever heard of a tablet whining and from what i read in this thread is sound like you got noise from a wire being too close to something or it could be some thing built in your home that makes it do that. My phone does it and its because of the materials that my house is made with as soon as I go outdoors it goes away.
Any device with an electronic power supply will hum, buzz or whine, it's caused by the nature of the power supply. Almost everything these days uses switched mode supplies, that's because they are much more effecient than the older style linear transformer supplies. This is why most of the plug packs you get for routers and phone chargers and the like are all very light now, the electronic components are far lighter than an iron cored transformer.
Put your ear to one of these plug packs next time you plug it in, you'll notice that it will be buzzing slightly. The trick is not in making a silent power supply, but in masking the sound. A hardware designer will take this into account when building the supply, but sometimes the components may not be built to the same standards as the rest, causing "soft faults", which are faults that don't get caught in the factory, as the device still functions.
What I'm getting at is, just about everything hums, how loud the noise is depends on the original design of the product, and the quality of the components that make up that design, if not enough thought was put into the design, or if the components aren't up to the standard that the design calls for, the sound may be more noticeable.
To be honest, the sounds supplies make don't bother me, as nothing will ever be so loud as a CRT TV. I can't tell you how many headaches I used to get as a kid because all I could hear all day were our lovely computer monitors. With LCD and plasmas everywhere, the world is a quieter place.
If anyone is interested in the technologies behind power regulation, I've included a few links.
Switchedmode Power Supplies (most common today): Switched-mode power supply - Wikipedia, the free encyclopedia
Transformer based linear supply (older and heavier): Linear regulator - Wikipedia, the free encyclopedia
Regards, Mike.
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