In monitoring some of the problems and complaints people have had with their Lumia 920 (every new smartphone has some issues at launch) I figured I'd put together a checklist of things to test for as well as possible solutions, so that we'll know whether to keep the Lumia 920 we bought or exchange it for another while we can.
Battery drain
Some people are reporting that their battery power is drained after just a few hours. Solutions: make sure only background apps you intend to run are actually running; close out of apps when you're not using them by pressing the back button; let the phone go through a few charging cycles; Nokia Drive running in the background is a common culprit - look out for the accompanying icon and be sure to close out of it and other apps properly.
Dust under screen
Only read of one such complaint. My guess is this is a one-off. If this is an issue the only solution is to exchange your handset.
Freezes/restarts
This seems to be happening quite frequently. People have reported freezing and/or restarting while doing the following: installing apps, using bluetooth, using NFC, and playing games. Test all of these things and ensure that your phone isn't freezing. If it does this often, exchange your Lumia 920 for another one.
Sound from speakers crackling/distorted/stuttering
People report that this is happening especially at higher volumes. Others are hailing how loud and crisp the sound is coming out of their Lumia 920 speakers. Obviously it makes sense to test this (with music, ringtones, etc.) when you get your handset. If you experience these problems, you probably need to exchange your handset.
Vibration rattle
This might not even be considered a defect. This is just how the phone vibrates. The Lumia 900 was the same. There's no need to exchange your Lumia 920 for this issue.
Green spot in front-facing camera view
One or two members have reported an odd green spot appearing in the view from their front-facing camera. This is a defect and you should exchange the device.
Overheating
This has been another widely-reported one. This is somewhat subjective and partly depends on what devices you're used to. Still, some have reported the phone gets uncomfortably warm, while others say it stays cool to the touch. If you're experiencing this, check to make sure there aren't a bunch of apps running in the background (things like Nokia Drive). Overheating is typically synonymous with heavy battery discharge, so ensuring there aren't too many apps running is a possible solution. If you're sure that isn't the issue, you should consider swapping out your Lumia 920 for a new one.
White colors appearing "greyish"
It seems whites aren't quite as vivid on the display as they were on the Lumia 900 for instance, and have a slightly greyish hue to them. This doesn't appear to be a defect, just how the phone is. Some don't even notice. This isn't something that will be fixed by exchanging your device, so hold onto your Lumia 920 if you have no other issues.
Daytime photos
We all know how great low-light photography is with the Lumia 920, but some people are complaining that daytime photos aren't as sharp as they should be. It's said that this is merely a software issue and that Nokia will be fixing it soon. This doesn't appear to be a hardware issue, so if it's not too bothersome, keep your device. Apparently fiddling with some of the settings will fix this, but nobody wants to do that every time they use the camera during the day, hence the pending Nokia fix.
Bluetooth pairing
A number of members are reporting problems pairing their Lumia 920s to their vehicles. Some have reported that pairing worked just fine, so this isn't universal. It is widespread however. So far no solution to this has been found. Best thing to do is monitor what people are discovering about the problem before exchanging your device. Also, try pairing your Lumia 920 with various devices to ensure it isn't a wider problem with the phone.
Am I missing anything? I plan to run through this checklist when I get my yellow Lumia 920 (hopefully this week).