Opinions in our hobby can be divisive, but we all agree: FPV is complicated. It takes a lot of time, research and practice to get in the air—but that’s only the beginning. Once you’ve crashed, it can be just as difficult to figure out what’s not working. In this article we’ll cover some troubleshooting strategies that will help you quickly pinpoint what’s wrong and determine how to fix it.
Learn what each piece does—and doesn’t do
Become very familiar with how your drone actually works. Each component has a specific job to do and requirements that it needs to operate. Looking at each component, ask yourself: “Why is this here?” “What does it accomplish?” “What makes it the best tool for this job?” “What does it need to operate?” Understanding what all of these are is critical to effective troubleshooting.
Just as important is understanding what each piece is capable of. This can really help you narrow down the root of a problem. If your image is coming through with the wrong colors, you’ll want to start troubleshooting with the camera—it’s responsible for generating the picture. If you’re having issues with control or FPV range, the camera can be safely ignored because the camera works the same way whether you are close to it or far away. This is a really obvious example, but you can usually apply this idea to rule out several causes of an issue.
When there’s a problem, you need to gather as much information about it as you can.
Use all of your senses. Look for things that are discolored, missing, or out of place. Listen for oscillations or unusual sounds. Feel for loose parts or hot areas. Even smell can be a troubleshooting tool to direct you to a problematic component.
It’s important to understand under what conditions the problem occurs. Are you in flight? Close or far away? How much time passed since you plugged in or took off? How hot is it outside? Does anything about your situation seem unusual? Has anything about your setup changed recently?
Some things will simply come with experience: WiFi interference looks a certain way in the goggles; a loose prop makes a tell-tale whine. You’ll become more efficient at troubleshooting as you go along, but being observant will always help you from the simplest to most complicated problems.
Isolate the problem
When you have a general idea of what’s wrong, try to narrow it down further with a few specific tests. Your goal is first to reproduce the problem. Yes, you need to intentionally make it occur again! After doing this, you can make changes to your situation to see if they contribute to or resolve the issue. For example, getting closer or further away, going fast or slow, switching batteries—all easy adjustments to observe and collect more information.
If that sounds like the scientific method, you’re spot on.
Come up with a theory, then test it
When you have some information about the problem, pause your data gathering and try to decide what may cause the issue. Based on your observations, what components could cause the problem? What can you eliminate from consideration? For really elusive issues, another approach is to just make some wild guesses.
In either case, set out to prove or disprove your theory. Do you think it’s a settings issue? Save your configuration and do a full reset on the flight controller. Is it actually a goggle problem? Try a different pair. Electrical issue? Run some checks with a multimeter. Do you think it’s a camera problem? Swap it out. Depending on what happens, you will confirm or eliminate your theory and have more information to move forward on.
Have spares on hand
You can only swap out parts to troubleshoot with if you have extra parts. It can be expensive to buy them for this purpose, so it’s great to have an alternate source for troubleshooting purposes. You might be able to make use of your local community. Friends who fly can often lend parts for testing. Over time, you may end up with an older quadcopter that you don’t plan to fly again. Don’t throw it away!
Having spare parts on hand is really valuable, even if you don’t intend to fly with them. Parts you don’t care about can be even more useful than a brand new replacement part. If your VTx is dead but the problem is actually the voltage regulator it’s connected to, putting in another VTx may just cause the replacement to break as well. It would be much better to learn this from an old part you don’t mind losing.
Being able to swap out parts just for testing can help you confirm a theory. If you have a drone that won’t cooperate, you can replace it piece by piece until it does.
Ask for help—the right way
Sometimes, we just get stumped.
The FPV community is, by and large, very interested in helping others stay in the air. When you need help, ask for it! Find a forum, online group, or a local gathering.
When you do ask for help, provide as much information as possible. Other people won’t have your experience with your own equipment, and won’t be able to run tests on it remotely. Stating something like “video doesn’t work” is not helpful. What do you actually see? Whether you have a black screen, broken-up picture, or pure static is much more important to someone who tries to help you. When you post, explain everything you can see, hear, smell, or feel. Equally important: explain how you have tried to fix it so far and what the results were.
Be prepared to answer questions. If you’re not responsive to others, they often can’t help you. When you ask for help online, be sure to check your post frequently, run tests that are asked of you, and provide clear information about the results.
Asking for help is not failure. Even the most experienced builders run into odd issues they need to ask about.
Keeping a quadcopter flying is a challenging endeavor, and absolutely everyone runs into issues that need to resolved to stay in the air. Bolstering your troubleshooting skills in the long run will save you both time and money.