Mickfo... I just wanted to narrow things down a bit more. There were some people in an XDA thread suggesting it might be from overheating the device (which would be far more common in lower signal areas when more power is being sent to the radio). Since it was so reproducible for you, do you know if the device was always quite warm when it happened? If not, I'm completely sold on it being a radio issue (whether it's hardware/software, I wouldn't be able to tell yet). Thanks in advance!
Just joined to share my experience with this issue. I've had the HTC One since it launched on Verizon and this issue has occurred to me a handful of times. Each time I was at work in a low-signal area. My phone will typically jump from 4G to 3G to 1X to no data signal throughout the day until I leave the building. The ringing has never happened to me outside of work.
I've spoken to both Verizon and HTC technical support. The Verizon rep said that HTC is working on a fix, but HTC doesn't seem to know much about it. Like another user above, the HTC representative asked that I try putting the phone in safe mode in case a third-party application that I installed was causing the issue. The next time the ringing occurred (about 30 minutes ago), I rebooted into safe mode and, to my dismay, the ringing started back up again about two minutes later. Rebooting back into normal mode, the ringing again started about two minutes later. A third reboot, again into normal mode, has stopped the ringing for now.
I haven't yet tried playing with the fast boot option like others have been discussing.
@dsblade, @CalebSpronk, the next time it happens, can you try "Airplane" mode and report back? I think this will help discriminate whether it's due to signal strength, etc. because "Airplane" mode turns off the radios, right? For example, if the ringing *does* occur while in "Airplane" mode, then I think we can conclude it is *not* a radio related issue, whereas if turning on "Airplane" mode causes the ringing to stop, then I think we can conclude it *is" a radio related issue.
Almost anytime we go indoors (especially deep inside a building like at work) our receiver signal strength is going to drop, and the RF power amplifier has to transmit a higher power signal to reach the cell tower.
I'll give it a shot. I'll also make a small note that there is an option to play an alert when roaming, but I've had that disabled and my phone never actually starts roaming.
@dsblade, I just saw Mickfo's reply in which it not only occurs in Airplane mode, but also when the phone is shut off (bizarre)!
This suggests that it is not related to radio, right?
To my understanding, the only actively running circuitry when the phone is *off* (and not charging) is the battery monitoring stuff (charge level, temperature).
On the other hand, when the phone is shut off, the power supply can still have residual charge (bypass capacitors), which eventually leak off. There could be a small bypass cap which leaks quicker than a larger one and the charge-sharing between them causes current to flow and if it's in the speaker power supply, it could resonate and create ringing. But eventually, the charge should leak off and so if it's related to this, the ringing should eventually stop. So, if it's making a ringing sound *while the phone is off*, then I would try to keep it in that state and see if it eventually goes away, which suggests it's a power supply related cause.
While I know it can happen while the phone is off, I'm still guessing it's a radio issue:
1. The noise goes away when you turn the device off WHILE having Fast Boot turned off. Note that just having Fast Boot turned off won't keep the ringing from happening, it only aids once you finally do a reboot or shutdown.
2. My guess is that when the device is turned off with Fast Boot on, it's not really fully off. I wouldn't be surprised if the radios are one of the few things still remaining on. I'll admit that this is speculation being as I don't know what's actually happening when the device is off with Fast Boot on.
3. Just because you turn airplane mode on while it's already ringing doesn't fix the problem doesn't necessarily mean it's not a radio issue. Maybe the radio is stuck in a certain state that won't be fixed until a certain signal is sent to it (such as the new call signal or full restart signal). If you know of an area where you can reliably reproduce the noise, I'd love to see if turning on Airplane Mode BEFORE the sound starts would keep it from happening. Being as I was driving (and can't remember exactly where) when it happened to me, this is a bit unrealistic for me to test at the moment.
I've never had it occur with the power off, as I typically have it powered 24/7. I'm a software guy, myself, but I wouldn't be surprised if someone told me that the radio pings the towers every now and then even when the device is off.
I'm not sure what kind of sound you're thinking of when you say that the speaker could resonate, but it literally is the sound of a phone ringing (with evenly-spaced delays between the rings). I typically have headphones plugged in and the ringing will play in my headphones (the first time it happened the volume was at a default deafening level, since then, I suppose something has changed and it now plays softly). Unplugging the headphones causes it to be played through the speaker. Because of this, I'm thinking it's more of a software-controlled issue (whether or not it's triggered by a hardware event such as poor radio signal, is currently beyond me).
@CalebSpronk In response to your third point, my phone is in the exact same location every day. However, this typically only happens once a day (or every other day). It seems impossible to predict when the ringing would start.
As another data point, just adding my experience of this issue, FWIW:
Not helpful to troubleshooting, but kinda funny:
When I first experienced this I was parked at a gas station. I heard faint ringing that went on and on. Because it was faint I figured it was a land-line phone ringing inside the office...and I wondered if the gas station folks were going to answer their phone...and wondered why their phone was ringing that long.
While I was driving I had my vehicle sound system cranked up so I didn't hear the ringing except when I parked and turned the music off.
BTW: When is Verizon going to start an HTC One Forum??
@dsblade, thanks -- all my line of inquiry was assuming it was some type of RF or power supply related audio interference which would be more like a tone or a buzz. From what you are saying it sounds totally software generated (and hopefully fixable). That's also consistent with why it would happen on VZW but not on another carrier (different sw).