After seeing the help provided by Colin-e l l *** in the CPU speed BIOS bug thread for this model, I would like to bring the following issues with the XPS 15 9550 to Dell's attention, and hopefully receive some advice or a resolution. I'm not listing issues that are likely due to 3rd party drivers (Intel graphics crash), and they are listed in priority:
Coil Whine: My model has fairly significant coil whine while on AC power. This squeaking noise is most pronounced while cold booting the computer, and is less audible on battery power. I have the latest BIOS installed
Fan while charging: While charging the battery and until it reaches around 90%, the fans run at high speed that is very audible. I do not have express charge enabled in BIOS or Dell Power Command, and have optimal as the fan setting. This has been reported by other, but not all, XPS 15 owners
USB-C Powershare: I use a USB-C to microUSB cable to charge my cell phone, but it does not charge when the laptop is off as when using the type-A USB ports. Powershare is enabled in the BIOS, and the phone does charges after logging into Windows. The latest Dell Thunderbolt 3 firmware was installed with no resolution. I have tried two different USB-C to microUSB cables with no change, and although this is not a huge issue, I wanted to mention it as the Thunderbolt 3 is advertised as having PowerShare and this would be convenient while traveling
I had the coil whine and space bar problems on the first 9550 I got. I just got my replacement unit and the space bar is good, and I don't think I have the coil whine as bad. Unfortunately, I'm now experiencing the fan's running constantly while charging below 90%. It's mildly infuriating because the core temperatures will all be below 30C and it won't ever turn off until I remove the cord. The fact that my last model didn't have this issue makes me question whether it is a software problem.
I'm running the latest bios (1.0.7). This is pretty much the only problem I have left and I really don't want to go through getting another replacement... If anyone has a potential solution to this, I'd love to hear it.