Hi, first time posting here. I am having an issue I am hoping someone can help me out with. I am in the middle of my first build of an Armattan Rooster using a CL Racing F4S. I just finished soldering up all the ESCs and I am unfortunately receiving a short tone on my multimeter when I test any + and - on the FC (Its not a long and steady like when I test 2 positives or 2 negatives, just a short beep). I desoldered the ESCs one by one testing each time to try to isolate the problem. I am now down to just the FC with the same results. Is the FC bad? I have done a thorough visual inspection and cleaning of the board. Not sure what to do now. Any advice would be much appreciated. Thanks!

No help with your current problem but I would buy or build a "SmokeStopper!" for future testing.

I just checked my DMM. I realized it does the same thing. As long as it is not on constantly, occasionally you will get a short beep. I am not sure why it does this, but I think you are safe. But I would make a smoke stopper like Lowlife mentioned.

I have a cheapy and a Fluke. I think you are safe.

I did some reading. Looks like it is the result of an uncharge cap. When cap is uncharge, it briefly acts like a short. Like I say before, as long as it is not continuous, you are fine.

Wow, thanks bro! That makes me feel better. Was pretty disheartened there for a bit.

Will definitely make a smoke stopper before I plug in.

You only need to suspect a short if the beep from your multimeter's continuity test stays on permanently. If it does, then it's time to look at the actual resistance reading.

At the moment you connect your probes, your meter is going to charge all the capacitors on your ESCs and any extra capacitors that you may have added on the PDB. This will make the continuity test beep briefly.

Whenever I'm installing a new board, I test it on it's own first. I have an adapter with alligator clips so that I can power up the flight controller and leave it powered up for a couple hours to make sure there are no problems. I also check the current version of firmware and update if necessary. If everything is OK then I'll proceed to install and connect the ESCs. If there's an issue, I don't have any problem with a return or exchange as the board hasn't been soldered and is still like new.

Thanks for the help guys. Really glad I joined this forum.