yashsingh1/xdaforums huggingface dataset:
[LG Optimus 4X HD] akshay aks:
HElp

My Optimus L3 2E425(jelly bean) has been rooted.successfully.after installing chainfire 3d...the problem starts

-My device is stuck at the LG splash screen after I selected normal boot from the 4X Touch Recovery app.

-When I try to enter recovery mode using Volume + and Power button, get the warning message from LG; "This mode is for data backup at service center..." and does not allow further. In short I am not able to boot in any mode.

-Is there a way to bypass the warning message from LG and enter recovery mode.

how can i overcome this..............plz help meeeeeeeeeeeee

---------- Post added at 03:29 PM ---------- Previous post was at 03:25 PM ----------

My Optimus L3 2E425(jelly bean) has been rooted.successfully.after installing chainfire 3d...the problem starts

-My device is stuck at the LG splash screen after I selected normal boot from the 4X Touch Recovery app.

-When I try to enter recovery mode using Volume + and Power button, get the warning message from LG; "This mode is for data backup at service center..." and does not allow further. In short I am not able to boot in any mode.

-Is there a way to bypass the warning message from LG and enter recovery mode.

how can i overcome this..............plz help meeeeeeeeeeeee
[LG Optimus 4X HD] SimonTS:
You are aware this is a totally different device? :eek:
[LG Optimus 4X HD] akshay aks:
wait...

:D sorry its my mistake.............my device name is LG optimus L3 2 E425 single..............................

my device has been rooted successfully by using Framaroot-1.4.1 ....then i found some apps for rooted device......then i found chainfire 3d after installing this...it ask me for reboot the phone...the phone reboots automatically.....after that.....it doesnt starts up.it stuck,,,LG logo only.................u got it
[LG Optimus 4X HD] SimonTS:
This forum is for the LG Optimus 4X HD. We use completely different methods to root and unlock our device, so don't expect to get any help here. Also, you should never just post your stuff onto the end of someone else's thread unless you are posting about the same thing - it's very rude.
[LG Optimus 4X HD] JoinTheRealms:
No one here can help, completely diferent device. Youu need to post in the forum specific to your phone if you cant find it post and the general android forum. Asking for advice on a device forum different to your device is a sure way to end up with a brick ;)
[LG Optimus 4X HD] LGaljo:
This is place where you can ask such question [MENTION=5745797]akshay aks[/MENTION]

http://xdaforums.com/optimus-l3-l5-l7
[Nexus 7 (2013) General] The111:
I just started playing a few games on this Nexus 7, and I turned the volume down to the lowest setting because it is late at night and other people in my house are sleeping. I immediately noticed a soft but very audible static buzz coming from the speakers... about the same volume as the audio itself. I held my ear up to the hardware and confirmed it is both top and bottom speakers.

Anybody else experience this?
[Nexus 7 (2013) General] smurfqq:
copyists sorpeno

I didn't notice at first. Noticed this morning with audio low as well.

I'd like to know if anyone else has this too. Kinda wanna know if its hardware since I purchased at best buy and only have 2 weeks to return.
[Nexus 7 (2013) General] Artood2s:
Yup, I was going to report this too, but since it only occurs at minimal volume I didn't bother. I lost my good headphones so I can test the audio jack. Does it happen to you with them on too?

Btw- if this the trade off with the fantastic (for tablet speakers) surround sound I'll take it. Watch the test video on the Play Videos app.

Sent from my Nexus 7
[Nexus 7 (2013) General] tweaked:
I don't hear it. on mine. But My hearing is horked.
[Nexus 7 (2013) General] siraltus:
It's because the Nexus 7 uses a crappy digital volume control that simply reduces the volume of the digital waveform before it hits the DAC, instead of having a real analog volume control -an op-amp that adjusts the volume of the signal before it hits the headphone/speaker amplifier.

What you're hearing is quantization noise as at the lowest volume the audio uses only 2-4 bits of dynamic range instead of the full 16 (or 24, dunno what DAC is in this thing). It's the same as the bit-crushing effect you hear in some dubstep and other electronic music that degrades the audio into a robotic crunchy mess, only here it's not on purpose, it's just cheap design.

There is nothing you can do about it.
[Nexus 7 (2013) General] ShimaMiku:
I've also noticed this (at first I was like, WTF? Is it raining in my game?). If what was said above is true, that makes me sad that nothing can be done about it.
[Nexus 7 (2013) General] smurfqq:
I'm not sure how you know that but if you're right I guess that means it would happen on all of them... which.. sucks.. Is there anyone that doesn't have this issue to disprove this?
[Nexus 7 (2013) General] siraltus:
I'm a professional audio engineer, I know exactly how these things work. Most cheap devices do volume controls that way, because adding a dedicated op-amp for analog volume control increases costs of the device, and the Nexus 7 is a budget device.

It does happen on mine, too, in every app that plays sound.
[Nexus 7 (2013) General] jayochs:
I love when pros come in here and give the technical explanation haha hats off to you, sir!
[Nexus 7 (2013) General] The111:
As the others have said, thanks for the explanation. Nice to hear from somebody who understands it, and if the problem is present in all units that actually makes me feel better since I don't have to worry about returning my otherwise perfect unit. :)

Question though, how come I don't hear the static when using headphones, even on the lowest volume settings where I hear the static from the built-in speakers? That makes me think it's related to the speakers and not the audio hardware... but you obviously know more than me on this.
[Nexus 7 (2013) General] The111:
Yeah, funny thing is the first game I played was Bad Piggies on some levels with an ocean tide moving back and forth at the bottom of the screen. I thought the static was the tide sounds... until I heard it in another game too.
[Nexus 7 (2013) General] The111:
It only happens at the absolute lowest volume setting... i.e. one notch up from muted. It sort of happens at the next notch up too, but is most noticeable at the quietest setting, and you need to be in a quiet room. I only noticed because I was using the device in a small echoey mostly tile room (you can probably guess where) and because of the room having such acoustics I put the device on the lowest setting just above mute.
[Nexus 7 (2013) General] TheCIScommander:
Had something like this on my original nexus 7

Except it happened regardless of the volume setting. Wasn't that audible- had to put my ear against the speaker to really hear it, but it did interfere with other devices, such as my radio, or keyboard with a head phone jack. It would make a sound like a quick DUH-DUH-DUH-DUH-DUH-DUH...DUH-DUH-DUH-DUH-DUH-DUH. My nexus 4 can sometimes cause static interference with other devices, too. Haven't gotten the new nexus 7 so I cannot say whether or not my new one has this issue
[Nexus 7 (2013) General] smurfqq:
Well.. mine's not only happening at the lowest volume notch. If I put it to my ear (never actually going to do this for normal use) it's there at every volume level, just hard to hear once whatever I'm playing gets loud enough. The display unit at a local best buy does the same. I can hear it in a quiet room at the first couple notches (normal use), which is annoying. Also, since someone asked - No it doesn't happen through headphones.
[Nexus 7 (2013) General] siraltus:
My pleasure! There's tons of FUD on XDA about many things, so I try to contribute on stuff I know well to reduce that.

Without looking at the schematics of the thing I can only guess:

The speaker amplifier is probably just a simple design that outputs 100% power all the time, so you have to control the volume of the signal that enters it, whereas the headphone amp probably has an integrated analog volume control.

A volume control is much easier (read: cheaper) to do in an integrated chip with low power signals (headphone out) than higher power (speaker out), and again, cheaper was the way to go with the Nexus 7.

Hence, there are two separate outputs from the audio chip - one that feeds the speaker amplifier and uses the bit-crushing digital volume control, the other outputs full-scale audio to the headphone amplifier which controls the volume in analog.
[Nexus 7 (2013) General] The111:
Makes sense. Thanks again.
[Nexus 7 (2013) General] paxunix:
Is this something they can fix (or at least mitigate) in a software update?
[Nexus 7 (2013) General] siraltus:
No, this is how the hardware is designed.
[Nexus 7 (2013) General] Lawlbringer:
Noticed this too from the speakers regardless of volume, and regardless of what is playing audio. It's a high pitched squeal to my ears which I can't stand. I've thrown out computer power supplies and video cards that have made similar(obviously, louder) noises.

Was hoping it could be something improved in software, but I guess not. Time to sell this. :(
[Nexus 7 (2013) General] Lawlbringer:
http://youtu.be/c9aQnuOrTY8

Recorded what it sounds like at lower volumes with a small condenser mic next to it. Let me know if that's similar to what you guys are hearing too.
[Nexus 7 (2013) General] xIJTIx:
For me it emits from top and bottom speakers. Now I'm wondering if even rma'ing it will do any good.
[Nexus 7 (2013) General] joey4321:
You might get a different result, but I sent my launch day nexus 7 (2013) for repair due to the static (it clearly has the static noise on low volume). sent it in got it back 18 days later and they didn't change anything since it passed the electronic tests.
[Nexus 7 (2013) General] inkogneetoe:
Don't RMA it. I did, they changed the main board in it and it still hisses. It even came back damaged.
[Nexus 7 (2013) General] xIJTIx:
Wow that sucks. Did you get reimbursed for the damage at least? Kinda lame that they won't do anything about the hissing. It's quite annoying when I'm using it at night.
[Nexus 7 (2013) General] inkogneetoe:
In dealing with them about the damage. Since 4.4.2 the bad distortion at low volume is gone but still a faint hiss.
[Nexus 7 (2013) General] r9800pro:
For me with 4.4.2 and 4.4.1 actually made it worse with my N7 LTE
[Nexus 7 (2013) General] Thalinor:
Thanks for the info; it was very informative. Subsidized in 2013 means cheep, like "conflict' is being used for "war" so they don't have to get congressional to invalid other countries. I am glad you called a pig a pig because whatever they try and dress it up to look like, it's still a pig. Nothing is really "subsidized" anymore it's now a term to used to describe how much of a [up front] profit margin is made companies. A better way to say it is "you are getting screwed a little less than usual."

My speaker volume on the N7 2013 is about the same as my old cr-apple iPod Nano, which has one single speaker that is about the size of an eraser head. Plugging in [good] headphones or using BT speakers do not help the low volume issue, which is why I figured it was just a crap design. I also have crackling too. I opened up the device to check to make sure the speakers were still ok and the membrane was in place; both were good. As you said, it's just a crap speaker designed to save money. I would love to see some hard numbers on the actual cost to make this device. You will find it's far from "subsidized" in the English definition of the word.

If you remember the American version of the GS3 had a crap WCD9310 hardware audio chip instead of the really nice Wolfson that was included on the International GS3. Ironically the international one was being "subsidized" by some overseas providers far more than the US companies were doing at release. T-Mobile was a perfect example selling the garbage American version with the garbage internals for more then any other provider here in the USA while they were selling the international device for a few euros, in both cases on contract. There were a lot of differences other than Quad vs Duel with Americans getting screwed at every turn; unfortunately, as usual, the corrupt American news media didn't report these to the public.

Get used to it people, greed has invaded our country and owns our politicians; both parties. It's only going to get [much, much] worse before it gets better. A storm is coming; just about every American can feel the cold rolling in and see the dark sky on the horizon.
[Nexus 7 (2013) General] The111:
Yeah, it terrifies me to think of a world where my children will have to survive on substandard digital audio toys. What a horrible world we live in.
[Nexus 7 (2013) General] Thalinor:
I am not going to start a flame war with you but if you are ignorant enough not to read between the lines, its your problem not mine. Your kids are screwed for much worse reasons then highway robbery on subpar devices. It's too bad most people are too busy wasting money on virtual farm games as real food supplies are dwindling, natural resources are running out, and everything is now controlled by a few of the wealthiest people on the planet. If you can't see the writing on the wall you are part of the problem not the solution. Just wait till the next war in Africa (bulk of the boots on the ground by 2016) for the last major cache of natural resources. Just watch.
[Nexus 7 (2013) General] player911:
Mine does this when I only play a video on mute. It goes away I bump volume up to 1.
[Nexus 7 (2013) General] metaxaos:
Have just purchased Nexus 7 lately. Manufacturing date is 2013-10. And it still has high-pitch coil-like buzzing from both speakers (more noticeably on top one).

It seems that for battery life reasons audio circuits are enabled only when sound is played and some time after that. Therefore -> when you e.g. tap some button, bottom speaker is on, sound is played and while no actual sound is present, high-pitch noise is audible. Half-second after bottom speaker is on, top speaker is also on. If you just tap the screen once then the sound is very short so it's not played on top speaker, but since it's on - it starts buzzing as well. After a second or so both speakers are off and buzzing ceases.

Therefore speakers start buzzing just as soon as their circuits are on. You could check it by lowering the volume till the minimum and doing some actions which make sound. You'll hear buzzing nevertheless you won't hear any actual sound. If there are some heavy computations when circuits are on, you'll hear louder modulated buzzing, like on some PC motherboards during heavy CPU load as well.

Thus the root cause is clear - audio circuits are just poorly isolated from CPU circuits interference. It seems like HW problem but ASUS haven't fixed anything for almost half a year. I'm not sure we could count on some SW remedy there... At least it'd be good if ASUS and/or Google made some official statement about it. In fact, I'm not sure how to react. I could make RMA without problems but other device won't make it better. And I still want genuine Nexus...
[Nexus 7 (2013) General] Matrix_19:
on kitkat 4.4.2, Google fixed it*

*this issue is not completely gone but definitely less loud for most people
[Nexus 7 (2013) General] Lendogg81:
The fact you are an audio engineer does not mean that is exactly how the Nexus 7 works, nor the source of the noise. Your own expertise and knowledge may be over-complicating the issue. I do not believe this is from the volume control being digital.

This issue is noticed at all volumes, however when the volume is high you cannot hear it very well because the audio drowns it out. The sound is the CPU being amplified through the speakers due to bad grounding/interference. It is very similar to the anomaly you would hear if you did not properly install the ground wire on a car audio amplifier. Each time the car accelerates you will hear a whining sound of the engine being amplified through your speakers. If you put your ear to the Nexus 7 when no audio is being played you can hear the very faint sound of the CPU which coincidentally is the exact same noise being amplified through the speakers when any audio is played.

This noise is not constant on the Nexus 7 because the speakers shutoff when no sound is being played and only turn on when audio is present. Now, either this is a battery saving feature or it is Google/Asus trying to cover up the fact that they did not engineer this product correctly without actually having to admit it. Our only hope is that they will do a recall and fix all of ours (NOT LIKELY!), re-engineer the product and fix them for those of us who complain, or we can return them and wait for a new build with the fix. Other than that, the only other option is a less popular one and would be in the form of a class action lawsuit once a new revision is released to fix this DEFECT.

I am very disappointed with this almost perfect tablet and will be returning it with my fingers crossed that there is a fix soon. I hope Google kills their partnership with Asus. I have owned many products from them and there always seems to be issues like this due to bad engineering. The fact that this issue got through QA is a joke, especially given the straightforward design flaw. Did they really not hear this in production, or did they and use the intermittent speaker on/off as a solution?
[Nexus 7 (2013) General] Lendogg81:
My gf took the tablet to work and compared it to a coworker's Nexus 7. Ours is louder than his. She said ours has the same sound his has, but more of a high pitched whine to it. So, I assume some are worse off than others unless mine has two separate issues. Lame, is being returned or exchanged soon.
[Nexus 7 (2013) General] siraltus:
And what is your expertise that lets you speak with such authority? Remember that on an internet forum your word holds as much truth as mine.

Also, there are two separate issues here. One is the quantization noise that I described; the other is the digital data noise that you described. They are not one and the same.
[Nexus 7 (2013) General] metaxaos:
Were both tablets at the same brightness level? If you get brightness to the maximum high-pitched noise will become kind of "crackling" instead.
[Nexus 7 (2013) General] Lendogg81:
. Hmmmm, interesting. You are correct. More evidence that this is a grounding/interference issue. We just texeted our friend to see of he used max brightness durng our comparison. If not, the QA is luck of the draw. I believe at this point both noises are grounding/sheilding related, but two seperate instances in which one is hit or miss unless our friend used max settings; in which case further comparisons will be done tomorrow.
[Nexus 7 (2013) General] karandevilocs:
mine makes some wierd noise when i attach it to charger and open an app or game Like CLASH OF CLANS i mute it and still the noise is there !?

is there any fix?!
[Nexus 7 (2013) General] Lendogg81:
Does anybody here have speaker noise with no high pitched whine/hum accompanying it (when not on max brightness settings)? Just thought a poll might help me and other determine if an exchange is warranted.
[Nexus 7 (2013) General] Thalinor:
When nothing is playing? If nothing is playing and you have speaker noise than you have a completely different issue. Most people here are talking about speaker noise while music is playing at various volume levels. If yours just makes noise while nothing is playing I would return it ASAP.

Did you get yours in the mail or via a retail location? If it was the mail... Actually I won't go there right now, been making too many waves as it is so I will go back to the shadows. Speaker noise out of speakers while NOT playing and NOT near max volume can mean several things, a blown speaker is one cause but there are others...
[Nexus 7 (2013) General] Lendogg81:
If you care to take the time to read my previous posts you will find that I fully understand that the speakers shutoff when not in use, and the sound only happens when they are active.

The reason I ask if anybody has no high pitched whine when on max brightness is that when on max brightness the high pitched whine is gone (or inaudible to human hearing) when the speakers are active on my device. My friend who I mentioned previously does in fact keep his Nexus on max brightness, so that is probably why his made less noise when compared to mine. Although, I am beginning to feel that my is in fact operating "normally".

So, as a quick "fix" just turn your screen on max brightness if the noise is bothering you, and if you are in a dark room and the screen is too bright on max settings, you just have to choose the lesser of two evils (or wear headphones).

Furthermore, I do not believe you understand the issue many of us are discussing here. This has nothing to do with blown speakers. The noise that we are all describing can only be heard clearly at low volumes as it is a background noise only present when the speakers turn on. Please, read through the thread thoroughly before posting irrelevant information.
[Nexus 7 (2013) General] Lendogg81:
This is the last I will post on the matter. Although my friend keeps his Nexus on max brightness, his tablet does not have the high pitched buzz/hum regardless of the screen brightness setting. It is a defect, and I will get an exchange tonight.

*Update* - Exchanged, problem persists :(
[Nexus 7 (2013) General] The111:
You know that even devices bought at retail stores spend a lot of time in shipping, right? These things are manufactured very, very far away from your local Best Buy.
[Nexus 7 (2013) General] oxxshadow:
I find it weird that on Stock Rom the issue is less noticeable, while on aosp ROMS like Purity it is
[Nexus 7 (2013) General] oldsoldier2003:
As a professional Audio engineer I bet that drives you nuts. I have tinnitus so it drowns out the buzzing lol!

/agree
[Nexus 7 (2013) General] oxxshadow:
So I guess there are no solutions... or even a way to make it less worse than it is

someone recommended installing Viper for Android... but I do not see how that will help
[Nexus 7 (2013) General] James101:
I have the same problem, and its pretty bad, at low volume I can hear, and high, it makes music sound terrible!
[Nexus 7 (2013) General] zschmeez:
Same Problem Here

I just noticed this buzzing while playing GTA Vice City on mute. My tablet is a 32 GB Nexus 7. It's manufacture date is August. I probably won't return this, but it's still a flaw I didn't expect. I hope Google comes up with something to fix it, or at least sends us all pair of ear buds so we don't have to hear the buzzing.

Edit: I am running Android 4.4.2 completely stock.

---------- Post added at 09:21 PM ---------- Previous post was at 09:02 PM ----------

I've had my Nexus 7 a week, and I've never noticed it until now. It seemed to just appear, like he said. Hope Google can find a fix for this.
[Nexus 7 (2013) General] Nysten:
You're the only one who has adressed the screen brightness. I tested your solution to max the brightness to make the noise go away and it worked (the noise is so small that you can't hear it)! This makes me really wonder whether the speakers have some grounding/isolation issues, or if it is software related.. The speakers seem to be interfering with the other components like the processor and the screen backlight and as others have said, the usb-port while charging.. I guess there could be a hardware fix for this, but it's not really something you could do by yourself. Maybe if ASUS would really look into what is going on, we could send our devices to be repaired and they could change the speakers with better isolated ones.. That would be the least they could do.

If the issue is software related, well, google would better be investigating already... The Nexus series is basically what represents google and their android right now. With these problems they are making a bad image if themselves. I hope google isn't turning into a super-greedy company, selling us **** and backing away from responsibilities.