I just bought the Nokia Lumia 930 and I have 5 complaints. All seem to be manufacturing defects. I'm a previous user of Lumia 920 and I upgraded my phone to Lumia 930 just yesterday. So I'm pretty sure they are defect. Here is what I'm facing:
1- My phone gets really hot from the bottom right corner while just holding it and using it very mildly. Simple tasks such as changing the settings on the phone would make the phone annoyingly hot.
2- Gray colors appear as purple hue in a dim environment when I have my phone on the lowest brightness setting.
3- Another issue with the screen is that similarly in dim surroundings and with brightness settings set at low, white screens (such as the one when opening a new tab in internet Explorer) tend to inconstantly flash making the screen look like it is getting insufficient power to fully maintain a white color screen.
4- The last issue I faced was when calling someone in dark/dim environments, the screens fades to black thinking that I'm holding my phone next to my ear. After it dims out it totally shuts down and won't allow me to interact with the screen. So I can't cut the line, I can't access and other functions in the OS. Other than the unresponsive black screen, from time to time the screen would stop responding to my actions. Such as pressing on a toast notification in the lock screen.
5- Battery drains pretty quick. I unplug the phone after charging it to 100%, and go the settings to tweak some stuff only to find out the 5 minutes later I'm down to 97 or maybe even 96%.