my laptop makes weird noise (some electric, buzzing noise). It happend if my battery level is 100% and AC is plug in. Do someone have same problem ? It probably issue named Coil Whine. Any fix? BIOS update ?
Hi, I have the same problem using Ubuntu 14.04 dual boot with win10.
One way to overpass his problem after boot is to logout from ubuntu and login again.
I get this error from dmesg:
[ 41.044920] [drm:si_dpm_set_power_state] *ERROR* si_upload_sw_state failed
[ 43.865577] [drm:gen8_irq_handler] *ERROR* Pipe A FIFO underrun
Edit: Logout and login just resets brightness. It seems that the issue appears when brightness is set to less than a half. So increase the brightness to overpass the problem until Dell solves it.
This kinda old post but I just found the reason of the coil whine. At least for my 7548 its the Monitor dim. I dont like brightness at night so I have my monitor dimmed at about 50%. Specially when there's no other noise around I can hear that annoying whine from the notebook (7548 touch screen fhd etc etc). When it was under warranty I was calling service but there was no whine because all the calls where in the day time and there were no whine because at those times I had the brightness full. So I couldnt explain to dell why its happening. Im writing now because I just realized it accidentally. Having brightness at less than 75% whines. 75% + No whine. (Im having this issue only when ac is plugged). Hope it helps if you havent thrown away this awful laptop yet.