My Photo Stream is a really cool function of all the Apple devices: iPad, iPod, iPhone and Mac, and guess what, you can even use this on a Windows PC, as long as it has iCloud. Because of My Photo Stream, you can sync photo from iPhone to iPad or Mac easily. However, this cool thing sometimes may have problems, for example, you can't find My Photo Stream on iOS 10 devices, My Photo Stream on you iPhone or iPad is not working, and My Photo Stream not showing on Mac. All of these problems can be solved within 3 minutes if you follow the guide here.
Don't mention that My Photo Stream not working, sometimes I even have trouble at finding it. My Photo Stream is in Settings>iCloud>Photos if your iPhone or iPad is on iOS 8/9/10.2. But, My Photo Stream in iOS 10.3 or later has been moved to Settings>Name>iCloud>Photos. You can find it there and tap it to open the function.
1.Change the format of your photos
My Photo stream support JPEG, TIFF, PNG and most files of RAW, but NOT Live photos and videos. My Photo Stream will not work if all the photos are Live photos. You could transfer those photos to the computer.
2.Find my Photo Stream in iCloud Photo Library
Apple officially said that when the iCloud Photo Library is on, you can find My Photo Stream on All Photos. It seems that My Photo Stream is not working, but it is, just in a different way. By the way, you may consider to turn off both of them if you don't need to sync photos from iPhone, that would make your iPhone run faster.
3.Log in with the same iCloud account
Make sure that you iPhone, iPad, iPod and Mac are using the same iCloud account. It's impossible to sync the photos from iPhone to iPad or Mac with a different iCloud account.
4.Keep ways from low battery
My Photo Stream will be turned off automatically by itself if the battery is lower than 20%. This is one fixed feature of My Photo Stream, you can't change that. Low battery means My Photo Stream not working.
5.Try better Wi-Fi connection
Please make sure that your devices are well connected to the Internet via Wi-Fi, Wi-Fi is important for both My Photo Stream and iTunes syncing photos from iPhone or any other devices.
6.Don't forget to turn off the Camera
All the syncing job will start after the Camera is off. Hence, if your camera is still on, My Photo Stream would not work for sure.
7.Fix system problems on Mac and Windows PC
Make sure your Mac is on the system OS X Lion 10.7.5 or later. The PC should be on Windows 7 or later and have installed iCloud for Windows correctly. My Photo Stream is not working on the earlier system.