Most projection screens come with a large black border, especially in 16:9 and 1:2.35 aspect ratio. Often, they will be right for your room, but sometimes, you need to reduce their height, so the image is at the right viewing height.
These adjustments are made on the motor itself and it's trial-and-error. You often go back-and-forth to get the screen. And then... the screen just stops completely and ceases to respond to any command.
After 5 to 10 minutes, it starts doing what it did last - like as it has a mind of its own now.
You call your supplier to get it replaced. Your supplier will tell you they don't know what is causing the problem and you need to send back the screen. But hold on, the following information will save you a lot of hassle and the cost of sending the screen back.
What's happening here - why does it stop and start?
It's actually a good thing.
It takes 5 to 10 minutes for the motor to cool down. It will then automatically finish the last command you gave. So it stops in midway when going down, it will roll down to its lowest position once cooled off.
Did you just damage your screen and what will happen when you use the screen on a daily basis?
The thermal protection system prevented you from damaging the motor. Even if it happens again, your motor will still be in perfect condition and will likely work for many years.
It's also very unlikely that this problem will ever occur with regular use. The motor doesn't get hot enough to shut down, even if you roll out the screen and immediately roll it back up again.
Conclusion
Knowing what's happening when you are adjusting the screen's settings from the motor's point of view can save you from jumping to conclusions. Many installers or on-line shops don't even know these things and would tell you there's a problem with the screen.
You know better know and will save yourself a lot of trouble and money in the process.
How Making Screen Adjustments Can Trick You Into Thinking Your Screen is Defective.