Kobo Libra buzz/whine when page turns

[Sirtel]

One of my laptops (a Lenovo Yoga convertible) buzzes almost constantly, especially when plugged in. It's not really like a coil whine either. No idea what causes it. It has buzzed since I bought it, almost 2 years ago now. As the laptop works well otherwise and has no other defects, I didn't bother to replace it. I've never heard any of my other electronics make a sound like that. My other laptop has a slight coil whine under heavier load, but that's a very different sound, and only rarely heard.

[stumped]

a buzzing sound from a monitor sounds different to a coil whine from a PSU under load ( having experienced both).

I recall some discussion of PWM flickering but not sure if that was with libra or another device. I wonder if PWM can also generate a buzz ( which goes away at 100% bright because PWM is then disabled) ?

[Sirtel]

Originally Posted by stumped

a buzzing sound from a monitor sounds different to a coil whine from a PSU under load ( having experienced both).

I recall some discussion of PWM flickering but not sure if that was with libra or another device. I wonder if PWM can also generate a buzz ( which goes away at 100% bright because PWM is then disabled) ?

Perhaps it does. Many Lenovo laptops have PWM, so possibly it's the cause of buzzing on mine. (I wanted to test just now, but the damn thing wouldn't buzz when I needed it to. Later, perhaps)

Edit: nah, it still buzzes even with the light all the way up.

[Quoth]

Originally Posted by stumped

a buzzing sound from a monitor sounds different to a coil whine from a PSU under load ( having experienced both).

Though both are usually magnetostriction. A ferrite core affected by the pulses.
405 TV 10.125 kHz
625 TV 15.625
525 USA TV 15.725 kHz
Basic VGA 31.450 kHz
50 fps progressive HD 56.250 kHz, but I've only seen 2 models of CRT able for that.
But the scan coils or the LOPT can sometimes resonate at half the frequency.

A SVGA or higher scan rate monitor whine is likely a SMPSU / DC-DC converter. Especially in a flat screen. A CCFL flat screen back light PSU can have a whine.

A DC-DC converter or other SMPSU in a gadget or a mains supply can be anything from 11 kHz to 2 MHz. The core or transformer is much smaller than the CRT LOPT core or scan coil cores. It can often be reduced by a dab of Silicon Rubber. Must be electrical quality as the DIY sealant type produces acid (possibly acetic acid) as it sets which corrodes coatings, pins, wires and joints.

So they do sound differently and older people can only hear the lower pitch whines, less than 14 kHz usually.

[geek1011]

My Clara also whines whenever the screen updates (but my Aura and Mini doesn't).

[pashtet]

I have returned my libra and bought exactly the same one from a different store. Unfortunately, the new one whines, just as much. Do, probably all the units are the same. I noticed that it is louder with some books though. My old Sony eReader does not make any noise with the same books, though.

[Joentjuh]

Originally Posted by pashtet

I have returned my libra and bought exactly the same one from a different store. Unfortunately, the new one whines, just as much. Do, probably all the units are the same. I noticed that it is louder with some books though. My old Sony eReader does not make any noise with the same books, though.

So far all those I've held in my hands did, but not all produce noise to the same degree. I've held one showroom model that if you didn't know what (and where) to listen for you wouldn't have heard it at all.

I returned mine and it's replacement is quiet enough that I don't notice it during normal use (hold it in landscape mode whilst reading) even whilst lying in bed where it's relatively close by.
Sadly the backlighting issue (orange/blue gradient) does seem to be the same for all.

P.s. Same with the Sony, loved it, but I've also come to really like my Libra. True it's not perfect, but if I had to buy a new reader it would still be a Libra.

[Sirtel]

It's probably the whole batch having the buzzing issue. My Libra (bought when released) certainly doesn't make any audible sound. I read mostly at night, in a totally quiet room, so I would hear if it did.

[Xullo]

Good morning. My Kobo Libra H2O also makes noise, I notice it especially at night, reading in bed...and it bothers me. I have the original Kobo firmware, would anyone know if installing Koreader or similar, this would be solved? Thank you.

[JSWolf]

Originally Posted by Xullo

Good morning. My Kobo Libra H2O also makes noise, I notice it especially at night, reading in bed...and it bothers me. I have the original Kobo firmware, would anyone know if installing Koreader or similar, this would be solved? Thank you.

I have no idea if this will help the noise, but you really should install the latest 4.20.14622 firmware. It's much better then the one you have.

[HolyAura]

I read in a quiet room with no sound at all, and I can only hear the sound from my Clara HD if i put my ear right up to it(which obviously i never do when reading).

[Joentjuh]

Originally Posted by Xullo

Good morning. My Kobo Libra H2O also makes noise, I notice it especially at night, reading in bed...and it bothers me. I have the original Kobo firmware, would anyone know if installing Koreader or similar, this would be solved? Thank you.

Depend on where exactly the problem lies in your model, I've heard of varying symptoms but most I believe can be traced to either low quality/faulty hardware components (not really my area of expertise).
So I think your options are:
- Return said device and get a new one if possible... and hoping for one without issues (look at batch/fabrication numbers).
- Change how you use it (I've noticed changing orientation make a big difference, even if it only changed the direction of the noise)
- Changing settings, i.e. try disabling/enabling WiFi
- Tweaking drivers might work, can be done manually I think (but wouldn't recommended trying if you don't know exactly what you're doing) or via firmware updates and hope Kobo managed to fix it... No idea what would need to be changed though and Kobo's changelog (if it can be called that) is rather less in-depth than I would have liked.

As I understand it, koreader is just an ebook reader, so switching to koreader would be like changing web-browser, (small) change in user experience and possibly an increase/decrease in battery drain, but no real impact on the actual device (since koreader doesn't replace the actual operating system, only a bit of what you see, think Android with only one fullscreen app). Correct me if I'm wrong though, not used it myself yet and not seen anything that would give more control over the device than the native app does.

[Xullo]

Originally Posted by Joentjuh

Depend on where exactly the problem lies in your model, I've heard of varying symptoms but most I believe can be traced to either low quality/faulty hardware components (not really my area of expertise).
So I think your options are:
- Return said device and get a new one if possible... and hoping for one without issues (look at batch/fabrication numbers).
- Change how you use it (I've noticed changing orientation make a big difference, even if it only changed the direction of the noise)
- Changing settings, i.e. try disabling/enabling WiFi
- Tweaking drivers might work, can be done manually I think (but wouldn't recommended trying if you don't know exactly what you're doing) or via firmware updates and hope Kobo managed to fix it... No idea what would need to be changed though and Kobo's changelog (if it can be called that) is rather less in-depth than I would have liked.

As I understand it, koreader is just an ebook reader, so switching to koreader would be like changing web-browser, (small) change in user experience and possibly an increase/decrease in battery drain, but no real impact on the actual device (since koreader doesn't replace the actual operating system, only a bit of what you see, think Android with only one fullscreen app). Correct me if I'm wrong though, not used it myself yet and not seen anything that would give more control over the device than the native app does.

Thanks for the answers.
I have already contacted customer service and they are offering to exchange it for a "new" one (tested by them).
Anyway, I will try to install Koreader, in case there is any improvement.
I think it's a pretty serious bug for a terminal of this price.

[JSWolf]

Originally Posted by Xullo

Thanks for the answers.
I have already contacted customer service and they are offering to exchange it for a "new" one (tested by them).
Anyway, I will try to install Koreader, in case there is any improvement.
I think it's a pretty serious bug for a terminal of this price.

Don't install KOReader. Just accept the new one.

[stumped]

Originally Posted by JSWolf

Don't install KOReader. Just accept the new one.

definitely- whine comes from hardware. e.g changing load on transformers, capacitors... it wont go away because you install alternative software.

I would however do these checks, for thoroughness
1. does having wifi on/off make any difference
2. does it happen in different places i.e. its not triggered by you sitting close to some emitter