• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

FT gremlin issues.

#1
This is my first post (if I put it in the wrong spot, my apologies)

I received the gremlin kit for Christmas, ive built multi rotors before and even helped a friend build his gremlin)

to start off im using a DXE radio (the cheap one with no screen) and the spectrum DSMX FPV Racing serial Receiver.

upon completing my build I was having trouble with beta flight, specifically the bind process. in the build video the instructions were to create a new model. I dont have the programming cable, is this flying a gremlin even possible without one? (programming cable)
also in beta flight all the sliders under the receiver tab were listed as 0 and i couldn't get the motors to spin

my problems only worsened, I had the board plugged into the computer and noticed beta flight said it only had 0.3 volts. so knowing that my reciever needed 3.3 volts, I plugged in my battery, everything looked fine (receiver went into bind mode) but then all lights died. I was looking at the screen when this happened but there was no smoke

now when I plug a battery in I get the auditory power up sound but No Lights and I cant connect to beta flight

Ive never had anything like this before. Please help!

Important update. after letting fc sit for several hours I plugged in a battery and light flashed for a moment. no sound and I cant seem to replicate that
 
Last edited:

PsyBorg

Wake up! Time to fly!
Mentor
#2
Would probably get more attention for quad copter issues if you ask in the electric multi rotor section but for now this will be OK.

Beta flight should not be reading any voltage when running on just usb power. To me that sounds like something may be wired incorrectly or possibly shorting and injecting some of the usb power into the main distribution of the flight controller. I would go back and check every connection with a magnifying glass to make sure nothing is touching two pads or that there is not a stay piece of wire touching another connection. These are common issues on these tiny boards and the small solder work needed.

As for the Spectrum gear specially the unit you speak of where programming cables are needed to change or make a new model that is out of my realm as I have never worked with something like that. Maybe JimCR120 could help you with that as he is a big Spectrum guy and has set up a Gremlin on Spectrum gear.

In the mean time go back over all of your connections and make sure they are all solid and clean with no stray strands. Maybe even wash the FC down with a toothbrush and alcohol to make sure.
 
#3
Hello Psy,

is it possible for me to move this thread where you said or should I just repost it there?

This is a silly question but would any of the esc connectors shorting kill my board like this?
I was under the impression that this would only be the battery lead soldering, which looked a ok to me.

The Board is most definitely Fried so ill have to replace that, I just dont want to spend another $20 to have the same mistake happen.
 

PsyBorg

Wake up! Time to fly!
Mentor
#4
I think the only way to move a thread is to have a mod move it. As it seems the board is definitely toast just start a new thread when you have a replacement and we can as a whole walk you thru any of the issues or questions you may have. These boards are very sensitive to shorts specially where the power distribution sections are. The regulators have a short time they can withstand a short but not long like 5 -10 seconds at most on the best of them.

It is always best when first powering on a fresh build or after any electrical change to use a smoke stopper. These can be easily made with a few connectors and a car light bulb. The light bulb will sink any excessive currents long enough to remove power form the system it is protecting so you can find the errors. I built mine to double as a battey drain for when I have full batteries that need to be stored for longer periods of time or to totally kill bad batteries safely before disposal.

smoke stopper.jpg
 

JimCR120

Got Lobstah?
Site Moderator
#5
Howdy ewokshoter,

I got your PM.

I do have a Gremlin and I do have Spektrum gear but I wouldn't consider myself much of an authority on either. I think I'm still working up to novice.

Regardless I am willing to help with the little I do know. I believe you and I have the same Spektrum receiver, the SPM4648 Quad Race Receiver I think it is called. Binding is fairly straightforward. Power up the receiver, let it go into bind mode, hold in the bind button while turning on the transmitter. Shortly after, release the button. The light in the receiver should go steady and if successful you should from then on power up the transmitter first.

If you're bound and the receiver and FC are all talking you should see the stick movement on BetaFlight. If you're not binding, sometimes it takes a couple attempts. I usually hold the transmitter upright and a arms length away from the receiver. Up close seems to adversely affect binding.

If you're not sure about what is working and what is not, try using known good with suspected bad to verify what's really going on. In other words, you said a friend also has a Gremlin. Is his also with Spektrum? If so you should be able to bind to his Gremlin with your radio or he could try binding his radio to your Gremlin.

Since you're new to the forum, how about a bit more about yourself? Where in the world do you fly? How did you get into the hobby? What have you built/flown.

Welcome to the forum.
—Jim
 
#6
Jim

About Myself:
I started flying model planes back when I was 12 or so and always loved aviation. Ive gotten into multi-rotors within the past year and even work at a program where part of my job is to help build racers (done as an engineering project) there arent too many places to fly around me so I mostly fly micros (tiny whoop has become my new favorite!)

My friends gremlin:
No he has Frsky


Ive found that the dxe should be compatible with the receiver im just unsure about how to get it all set up, before the board was fried the receiver would have no light while powered until I turned on my transmitter at which point a solid orange light would turn on.

I think Ill order that new board, pout my way through the painful shipping time, and re-solder. Ill make sure to post magnified images of the whole board before I plug in any power. does that sound like a good course of action?

thanks for the warm welcome,
Ewok