Surface Pro 4, annoying noise from the back!

Hello GiovanniSm

When did this start happening?

Can you confirm that Surface is fully up to date?  Did all updates install successfully?

Do you notice this happening under other circumstances, beyond dimmed screen?

Best regards 

John1F, is it possible to get any response from Microsoft concerning this high-pitched noise problem?  I am trying as hard as I can to keep my $1400 with Microsoft on this Surface device + accessories  - I've spent hours and hours (around 15) talking with Microsoft techs on the phone and in person, I've made multiple trips to Microsoft stores and spent a lot on gas, I've spent a lot of time problem-shooting on multiple devices... but still I have not heard anything concerning whether Microsoft will address this issue.  Like I said, I am trying as hard as I can to keep my money with Microsoft, but I can't spend $1400 on a device that hurts my ears when in a quiet room.  I only have a couple weeks left before I can no longer return the device.  If I don't find out whether the problem will be addressed, I'll have no choice but to return the device - not because I don't like the device, but because it hurts my ears when studying.  :-(

Could also be the LCD backlight driver. These are often run by switching regulators and the sound would spread across the LCD. Try use the device without running suggested brightness. It could be that on suggested brightness the regulator doesn't stabilise completely before the set point in brightness is changed (this would be pretty simple to fix in firmware, just limit the update rate of the brightness)

Do you think there is anyone in Microsoft who could give an answer on whether this is definitely fixable via firmware?  I don't have much time left before I have to decide whether I'll return this device :-(

Could also be the LCD backlight driver. These are often run by switching regulators and the sound would spread across the LCD. Try use the device without running suggested brightness. It could be that on suggested brightness the regulator doesn't stabilise completely before the set point in brightness is changed (this would be pretty simple to fix in firmware, just limit the update rate of the brightness)

My current i5 is rock solid from noise issue either CPU electrical or backlight that not had either the two m3 I returned.

But I will return my i5 due to other issue the proximity sensor of the screen is broken and defective and not behave normally.

The manual setting of brightness is not working at all and act as automatic brightness setting.

After 3 SP4 unit I'm done for good with surface tablet after 2.5 years having work with free of issue SP2/3 and Surface 3.

MS should improve the quality control on SP4.

Now I'm thinking new thinkpad x1 tablet as alternative proposal.

Unfortunately, I've tested multiple SP4 i5 units for this backlight noise, and it has been present on every unit.  I've had two replacement units for my purchased unit, and every unit I've used has had the backlight noise. I'm not sure if this is present on other units.  I can handle the fan noise and clicking noise of the CPU, but this high-pitched whine from the backlight brightness drives me crazy.