This tutorial shows you how to troubleshoot and fix a quadcopter that doesn’t arm. I will also explain the common problems that prevent a mini quad from arming with Betaflight.
If you are completely new to Betaflight, check out my tutorials on how to setup it up for the first time.
The first things to check
Here are the first things you want to check when you are having trouble arming your quad:
- Radio receiver is bound and working correctly in Betaflight. Check in the receiver tab if the channels are responding to sticks movement in the correct order and direction (download the latest betaflight configurator)
- Check if you have assigned a switch on your radio for ARM mode, and if it can be activated by that switch. The arm mode should turn yellow when activated, indicating that the switch is working
- As a safety feature in Betaflight, the motors won’t spin up even when you arm it if the flight controller is connected to the configurator. Remove USB connection and try again
If everything is good but you still can’t arm the quad, then we will have to look a bit deeper.
How to check for arming issue in Betaflight?
If you have Betaflight OSD, make sure you display “Warnings” on your screen, and that “Arming Disabled” is selected. This will let you know what is stopping arming.
If you don’t have Betaflight OSD, you can also check for the “Arming Disable Flag” in Betaflight. This will indicate the issues that are preventing you from arming.
There are multiple ways of checking for “Arming Disable Flag”:
- Betaflight Configurator
- CLI
- Buzzer Beeping
Table of Contents
Betaflight Configurator
If you have access to a computer, you can easily check the Arming Disable Flag in the Setup Tab in the Betaflight configurator.
CLI
Alternatively, you can check in the CLI by entering the command “status”. The last line of the status info is arming prevention flags list. This feature was made available after Betaflight 3.2.
Further Reading: How to use CLI in Betaflight?
Buzzer Beeping
If you don’t have access to a computer, but you do have a buzzer in your quad, the beeping should also indicate the reasons for the disabled arming. The beeping pattern can be broken down into:
- five short beeps for attention, which can be ignored
- a number of long beeps
- a number of short beeps with long intervals
Each long beep represents 5, while each short beep represents 1. The final flag number can be calculated as 5 x <the number of long beeps> + <the number of short beeps>.
For example:
- 0 long beep and 2 short beeps = 2
- 1 long beep and 3 short beeps = 8
- 2 long beeps + 0 short beeps = 10
Arming prevention flags lookup table
Once you have found the arming disable flag numbers or names, you can look it up in the table below to see what they actually mean. The table was taken from the Betaflight wiki page for our readers’ convenience.
| Name | Description | Beep code | Required Actions | |||||
|---|---|---|---|---|---|---|---|---|
| 3.2 | 3.3 | 3.4/3.5 | 4.0 | 4.1 | 4.2+ | |||
NOGYRO | A gyro was not detected | 1 | 1 | 1 | 1 | 1 | 1 | You may have a hardware failure, if a previous firmware version works then it may be a firmware issue. |
FAILSAFE | Failsafe is active | 2 | 2 | 2 | 2 | 2 | 2 | Rectify the failure condition and try again. |
RXLOSS(1) | No valid receiver signal is detected | 3 | 3 | 3 | 3 | 3 | 3 | Your receiver is either faulty or has no link to the transmitter. |
BADRX(1) | Your receiver has just recovered from receiver failsafe but the arm switch is on | 4 | 4 | 4 | 4 | 4 | 4 | Switch the arm switch off. |
BOXFAILSAFE | The ‘FAILSAFE’ switch was activated | 5 | 5 | 5 | 5 | 5 | 5 | See FAILSAFE |
RUNAWAY | Runway Takeoff Prevention has been triggered | 6 | 6 | 6 | 6 | 6 | Disarm to clear this condition. | |
CRASH | Crash Recovery has been triggered | 7 | 7 | Disarm to clear this condition. | ||||
THROTTLE | Throttle channel is too high | 6 | 7 | 7 | 7 | 8 | 8 | Lower throttle below min_check. |
ANGLE | Craft is not level (enough) | 7 | 8 | 8 | 8 | 9 | 9 | Level craft to within small_angle degrees (default 25). |
BOOTGRACE | Arming too soon after power on | 8 | 9 | 9 | 10 | 10 | 10 | Wait until pwr_on_arm_grace seconds (default 5) have elapsed. |
NOPREARM | Prearm switch is not activated or prearm has not been toggled after disarm | 9 | 10 | 10 | 10 | 11 | 11 | Toggle the prearm switch. |
LOAD | System load is too high for safe flight | 10 | 11 | 11 | 11 | 12 | 12 | Revisit configuration and disable features. |
CALIB | Sensor calibration is still ongoing | 11 | 12 | 12 | 12 | 13 | 13 | Wait for sensor calibration to complete. |
CLI | CLI is active | 12 | 13 | 13 | 13 | 14 | 14 | Exit the CLI. |
CMS | CMS (config menu) is Active – over OSD or other display | 13 | 14 | 14 | 14 | 15 | 15 | Exit the CMS (or OSD menu). |
OSD | OSD menu is active | 14 | 15 | 16 | Exit OSD menu. | |||
BST | A Black Sheep Telemetry device (TBS Core Pro for example) disarmed and is preventing arming | 15 | 16 | 16 | 15 | 16 | 16 | Refer to the manual for your hardware. |
MSP | MSP connection is active, probably via Betaflight Configurator | 16 | 17 | 17 | 16 | 17 | 17 | Terminate the Betaflight Configurator connection (disconnect). |
PARALYZE | Paralyze mode has been activated | 18 | 17 | 18 | 18 | Power cycle/reset FC board. | ||
GPS | GPS rescue mode is configured but required number of satellites has not been fixed | 19 | 18 | 19 | 19 | Wait for GPS fix or disable GPS rescue mode. | ||
RESCUE_SW | GPS Rescue switch is in an unsafe position | 19 | 20 | 20 | Turn off the GPS Rescue switch to arm. | |||
RPMFILTER(2) | Motor RPM-based filtering is not functioning | 21 | 21 | 21 | One or more ESC’s are not supplying valid RPM telemetry. | |||
REBOOT_REQD | Reboot required | 22 | 22 | Reboot the flight controller for settings changes to take effect. | ||||
DSHOT_BBANG | DSHOT Bitbang is not working | 23 | 23 | (3) | ||||
ACC_CALIB | Accelerometer calibration required | 24 | Calibrate the accelerometer or disable features that use it | |||||
ARMSWITCH | Arm switch is in an unsafe position | 17 | 18 | 20 | 21 | 24 | 25 | Toggle the arm switch to arm. |
Other common issues that stop the quad from arming
If you don’t get any arming disabled flag in Betaflight, then the problem might be something else. Try to go through the following check list.
Accelerometer Related
Maybe your mini quad is not on a level enough surface, or the ACC (accelerometer) is not calibrated. Calibrate ACC on a level surface first, if still no luck, try increasing “small_angle degrees” in CLI (default is 25).
Or simply disable ACC if you don’t fly Angle mode.
CPU Usage Too High?
When CPU load is too high, the flight controller will simply refuse to arm. Try to stay below 50% by lowering looptime, and disabling unnecessary features.
Throttle Related
Check if the lowest value in your throttle channel is too high, make sure the throttle stick is at its lowest position when attempting to arm. Ideally every channel including throttle should have endpoints of 1000 and 2000. If they are not then you might want to calibrate your radio endpoints first.
Betaflight doesn’t arm if your minimum throttle is too high (higher than the setting “Min_Check”). This is a safety feature so that the quad doesn’t suddenly spin up the motors and hurt you when it’s armed. You must ensure that your throttle is lower than min_check when it’s in the lowest stick position. Min_check is set to 1050 by default, double check if it’s not been changed by mistake.
Moron threshold
Some FC might have more sensitive gyro’s and the quad would refuse to initialize after power up, and therefore you can’t arm it. By increase Moron Threshold in CLI can reduce gyro sensitivity during initialization. Try setting it to 100 or even 120.
Conclusion
I hope that was helpful! Let me know in the comment if you had problem with arming that was caused by something else that wasn’t covered in this tutorial. If you are still having problems arming your quad after following this guide, please post your question on our forum, I am more than happy to help.
52 comments
I have a very interesting behavior: When I power the flight board via USB, RX is fine and I can see the stick movements in Betaflight. However, when I plug in the battery I immediately see the warning “RXLOSS” and also no more stick movements are displayed in Betaflight. As soon as I unplug the battery, the “RXLOSS” warning disappears and I can see the stick movements in Betaflight again as well. I have no clue what the issue for that might be. Do you have any idea? I am using a Futaba R3001SB Receiver.
Short Update: I did some further testing and it looks like the issue is somewhere in the Betaflight configuration, respectively the flight controller (I am using the SpeedyBee F7 V3). The problem mainly is that as soon as I power up my DJI O3 Air Unit, the flight controller reports “RXLOSS” in the “Arming disable flags”, while everything is fine when the DJI O3 is not running, which is the case when the flight controller is only powered via USB and not via the battery. However, it is not that the connection between radio and receiver is lost, it is more that something is wrong with the connection between receiver and flight controller. I tested it with FASSTest too and observed there the same problem as well. Probably I misconfigured the flight controller. Do you have any ideas what the misconfiguration might be?
Hi Thomas, did you manage to fix this issue? I’m having the exact same problem, with the exact same setup.
Many thanks,
Pepijn
Check if you have any other things connected to the same UART as the receiver? And if the 5V pad does output 5V when you plug in the battery with a multimeter? Maybe try a different UART?
I just got a rekon35 and a Expresslrs Jumper t-pro trans… I then ordered a HappyModel ep2 elrs receiver. I hooked everything up, Did the binding and firmware update. Bars on trans shows that I’m getting signal but light still flashes on receiver. Went to betaflight and getting ARM Disabled message. Looking over you web page on how to fix and not working for me, Can You help???
What’s the arming disabled flag? How to check: https://oscarliang.com/quad-arming-issue-fix/#CLI
Hey Oscar,
I keep getting the arm switch in unsafe position error. I toggle the arm switch and nothing. If I go into turtle mode and arm turtle mode works. If I reflash Betaflight it works for a bit, but then I plug the quad in an hour later and get the error again. Any idea what could be happening?
Thanks.
I am using a tango 2 pro, crossfire nano and speedy bee f7 v3
Probably means your quad is on an unlevel surface when taking off.
Go to configuration in Betaflight, Find “Arming”, and set the angle to a higher value.
Normally I set it to 180 degree personally. By setting arming angle to 180 effectively disables this feature, and so it allows you to arm the quad regardless what position the drone is in (even upside down). This is useful when you get stuck in a tree, you can still arm the quad, run the motors and get it out of the branches. If this is set too low you might not be able to arm it. By disabling the Accelerometer will also turn off this feature. More info: https://oscarliang.com/betaflight-firmware-setup/#Configuration
Hi Oscar, I had Flywoo Baby Nano FR 1s Elrs and it binds to my Radio Master TX16S but have no telemetry stick response nor arming. I have tried everything (re-flashed firmware CLI scrape from Flywoo etc.) and the only activity of stick movement is if I change to SBUS in the receiver tab in beta flight but the telemetry is sporadic…
Did you bind it to the 4in1 multiprotocol module in your TX16S?
Are you sure you bought the Baby Nano with ExpressLRS receiver or the Frsky version? It’s odd because you got SBUS working and not ExpressLRS.
Hi Oscar, I had Flywoo Nano FR 1s Elrs, already updated to V3 version on expresslrs configuration. Had conneted to Radio master Boxer Elrs, but when I turned the Arm switch, all the motor’s didn’t spin ? Would you please help me
Thank you
Once again you helped me figure it out, looked at the set up page and it said throttle setting too high. 10 min fix.
Thanks again
I got rx_failsafe flag and I have no idea what to do, please help
Is your radio working?
have you checked in receiver tab? https://oscarliang.com/betaflight-firmware-setup/#receiver
I recently started having issues with the scroll wheel on my jumper t16. I reseated the ribbon cable, updated the firmware. I went to test a pack outside to make sure things were 100% and my drone wouldnt disarm. I had to have it pinned upside down and run the battery out until it shut off. I plugged it back into betaflight (Props off of course) and checked for anything that seemed off. Everything is as it was before I had radio issues. Any clue as to why this happened?
Hello, Your article helped me when i couldn’t arm due to not enough satellites for GPS lock. Thank You for that. But i have a different arming issue this time and it seems it has nothing to do with arming prevention flags. I’ve flown with my quad for about four minutes no problem. Then i landed (gently no crash) and since then i couldn’t arm again.
Every time i try to arm, quad beeps three long beeps and thats it (no 5 short attention beeps). There is no arming prevention flag in betaflight configurator.
Since then i narrowed it down to ESC problem, because motors don’t spin even in betaflight configurator (with battery connected). Also when i plug the battery a get only first three beeps of that classical startup sound. Last two beeps “arming sequence” are missing.
I have no idea how to proceed now. Have anyone experienced this before and has some solution please?
Hello,
I can’t arm.
You write:
“Radio receiver is bound and working correctly in Betaflight. Check in the receiver tab if the channels are responding to sticks movement in the correct order and direction (download the latest betaflight configurator)”
That’s ok for me
“Check if you have assigned a switch on your radio for ARM mode, and if it can be activated by that switch.”
That’s ok for me
” The arm mode should turn yellow when activated, indicating that the switch is working”
That’s not ok for me. What it means if the arm mode does’nt turn yellow (it turns red)? Where does the problem come from?
I accidentally put my xjb-145 into bootloader mode , now it does nothing , how do I fix that
Hi my quad isnt arming, the motors dont spin but i get a response from the motor tab and i get input on the receiver tab when im moving the sticks but it doesnt spin the motors and only one motor just twitches and nothing else happens . I typed in status and there werent any flags. Do you know what the problem might be? All my end points are fine oh and i am not getting all 5 blheli beeps but i am set om the correct motor protocol
I’m using a i bus fly sky receiver and a blheli S 45a i flight esc with a mamba f405 FC the FC does power up and all my motors work the are all healthy i tested them.
I am hoping this isnt already gone over and over, but I am truly stuck and like others about to give up. I have a tiny whoop, dx6 g3 TX, the only arming disable flag I have is arm_switch. I have gone through all the settings in the TX and the modes in beta are setup right as it shows arm and failsafe setup properly. When I do flip the arm switch in mode tab, it shows ARM but red because it is (disabled). My arm switch and failsafe are the same switch in different positions. I have checked all the normal stuff and that is all good (min_check, throttle position, accelerometer). I am thinking it is a setup in my TX but I cant find it. I turned off motor cut as well no change
Im currently having trouble getting what’s now two tinyhawk 2 freestyle’s to fully start up after plugging both batteries in. Only half of the tune that plays during initial setup is played. Therefore when i attempt to connect either quad up to betaflight, no connection takes place.
Now this is after both of these quads fell from the sky and hit the ground,(roof & a yard, not the concrete either) and now as a result, i believe i may have damaged both of the flight controller’s on each quad. Im sure this is a common sense issue, but i am sure im overthinking the situation and being very optimistic lol. Thank you if th you could help!
FIX Update: Looks like the initial fix I posted was a fluke. It just worked intermittently when I changed that setting 3 times in a row. But after I posted this, the 4th time wasn’t a charm. However, I now can say with confidence that the new discovery may be the smoking gun. I had a R9 MM-OTA Rx installed ono the Tx2/Rx2 pads, but because I can’t seem to pair it I’ve been using the stock TinyHawk Freestyle 2 SPI Rx. After de-soldering the R9 MM, it works like a champ now…famous last words ;)
FIX: I was struggling to try to get my TinyHawk Freestyle 2 to ARM and all Flags in BetaFlight were showing no problems (besides MSP which is normal when checking other flags via BF). The one thing that solved my arming issue was in BetaFlight, go to the OSD section and disable (uncheck) the Warnings ‘Arming Disabled’. So excited to fly now, unfortunately, this took 2 hours to figure out and now it’s dark out SMH…
Hi, currently i’m getting “Rx_failsafe MSP” on the arming info, and getting the red arming disarm. I got a BNF DC3 from iflight and using DJI goggle and remote. I’m certain iflight would have it tested already so it just the matter of setting issue. I got my stick movement corresponding, not sure why?? One thing i noticed is under the Port tab, my UART1 Serial Rx is ON and my UART2 Configuration/MSP is ON, is this normal?? Also my Dji goggle i have to set it to CH1 in order to work, do you have a tutorial for DJI goggle channels??
Much appreciated for any guidance, thanks.
I don’t have this quad, so not sure how it’s setup exactly.
You can post some photos of the setup in our forum, IntoFPV.com, but we need more detail like how everything is connected together. Also we need to know what radio/protocol you are using to control the drone.
Or you can maybe contact iFlight customer support see if they can resolve this for you quicker.
I have connected my FrSky R-XSR receiver and enabled serial RX for the UART I used. I also set the Smart Port resource to TX1 and enabled that in the SoftSerial part of the ports tab. However, my receiver tab will not respond with my transmitters actions. Its stuck with all of the stick and aux values (that I have set) at the lowest point, just like in the first picture in this article. Any Idea what to do?
How to Setup SBus, SmartPort Telemetry
I’m giving up on drones they just to complicated to set up why cant they come ready to go as a newb it’s just so off putting it’s a shame I love fpv
Blog needs updating:
Beep codes have changed from BF 4.0 onwards.
github.com/betaflight/betaflight/wiki/Arming-Sequence-&-Safety
Thank you, I’ve added this to my to-do list.
I am new to mini quads and I would like your help with the following situation. My Trashcan worked normally with my Taranis QX7, and for no apparent reason no longer arm. The Trashcan and the radio bind, but don’t arm and there’s no reaction from the sticks on the Betaflight receiver tab. Only thing I did after last Trashcan flight was to add a DSM plane to the IRX4 + external module that is installed on Taranis. The Status command via CLI displays RXLOSS.
Hello
My drone won’t arm.
In my osd i get a warning hsp.
can sombody tell me what that means?
Gr Daan
Hi my quad isnt arming, I can spin the motors from the motor tab and i get input on the receiver tab when im moving the sticks but it doesnt spin the motors. I typed in status and there werent any flags. Do you know what the problem might be?
Im using a ppm receiver (CM703) and pwm ESC’s.
Thanks,
Hessel.
Hey FPV Friends,
after updating my Tbs Vendetta v1 to betaflight 4.0 i have a solid red led instead of the quad arming up. I checked and calibrated everything, i have a low cpu load… no beep codes at all (at least not anymore – see above ;-), no blinking, nothing.
It just won´t arm.
Maybe somebody has a suggestion for me :-)
Thx, Chris
What arming disable flags are you getting?
Can you try flash an older version of BF see if that works?
If this works, but not Betaflight 4.0, you should check with TBS.
Hi, thanks for this great tutorial. I’ve just built my first quad and set up the arming switch to aux 1 after following your guide. Betaflight shows the switch transitioning and the yellow indicator moving into the yellow band. However my quad does not arm. In my goggles OSD, the warning THROTTLE appears when moving aux 1 to arm. My throttle is in the minimum position already and i have also tried trimming fully back which makes no difference. Can you please let me know what the possible problem could be?
Thanks
1. At throttle’s lowest stick position, what value does it tell you in the receiver tab? Ideally it should be lower than 1000, e.g. 998, or 999
2. Make sure your Min_check is at 1050, your lowest throttle has to be lower than this value in order to arm.
Is the only way to know for sure if the flight board is toast is trial and error? I know that’s probably the last thing people hope it is , is that why people just don’t check that first or is there no direct way to check just the flight boards status? Sorry if this question is stupid, I’m a newb
It’s going to be too long a topics to cover in a blog comment, i will have to write a post for that in the future.
@Ash
It’s been a while and you should’ve (hopefully) resolved the issue by now. Just throwing this out in case it might be useful to someone else.
When I had the issue of the gimbals not responding in Betaflight, it was the Failsafe mode which I accidentally enabled on my transmitter. I could see all AUX input channels responding except those of the gimbals or of the ARM switch. Flipping the switch to disable Failsafe had everything working normally again.
Hello i just got a GEPRC Mark2 PNP quad. I plugged in my receiver which is for an Radiolink AT9, but as soon as i turn on my remote, the quad beeps constantly of short beeps. My OSD said “BADRX”, but the reciever works on my other quads just fine.
Receiver is probably not setup correctly.
I have no experience with Radiolink, please join up our forum and see if you can get help from our other members? http://www.intofpv.com
i have same issue try to check every point on the list. I have a flysky turnigy evolution . had tried spektrum dx8 then go for taranis x-lite but always came back to flysky t . . .
so i have also full controll and solid signal when i connect and whatsch the recivertap.
but radio’s endpoints says avery channel 100% . have no more ideas
Thanks for your detailed tips,it should had helped me and people just involved in,but I tried everything even googled lots of vids but still unable to make arm activated in Beta Flight configurator, however flip fail safe and fly mode switch work fine and beep, if I check all the tips,what else would I missed?
Please join our forum for troubleshooting: IntoFPV.com
I just started running TBS CROSSFIRE on my kwad. I was running FrSky R-XSR rx for months and no problems arming at att! Today December 9th is my first time flying crossfire module with the nano rx. My fc is the pyro F4OSD running betaflight RC3.5??? I think? Anyway, the kwad willarm once and if i disarm I get the “PARALYZE” flag? Can someone help me out with this one??
that’s a betaflight feature used for racing. Check your BF settings. Make sure you don’t have a mode enabled for Paralyze on accident
Hello,
I’ve just updated to the latest versions of betaflight (3.4 & configurator 10.3.1) everything works great, new PIDs and turtule mode are awsome.
The thing is it only seems to have Air mode, I can’t find neither angle nor horizon mode, where are they ?
Please help me.
Ed.
maybe you’v disabled accelerometer?
Was flying fine for days, had rough landing, wouldn’t arm after this, plugged into betaflight only to find not getting any response to the sticks/switches in the receiver tab. But Taranis xd9 tells me telemetry gained / lost when I power on or off. So it’s bound to receiver, some sort of communication but no sticks input.. spent a fair few hours trying to trouble shoot before asking here. Could be a wrecked Flight Controller board and I have ordered a new one today. (Using DYS F4 Pro v2). But more worried my Taranis xd9 broke somehow :(
My beeper is not very clear/loud but think its telling me error number 3. Beta flight says “arming disable flags: 3,17 And CLI “status” says RXLOSS (and the typical CLI and MSP).
Summary of what I’ve done so far:
checked wiring thoroughly, visual and with multimeter including the header plugs and inspected for bent pins etc.. re-soldered the receiver wires to fc board and re checked with multi-meter. No change.
2. Open brand new R-XSR receiver, bound it and plugged into the freshly soldered wires, successful binding but: – No change
3. I think every other troubleshooting option I’ve found on this page and on many vids (JB youtube for example), are to solve a problem that does not including having no stick response in betaflight – I still tried most of them – good learning experience
Any tips or suggestions welcomed! My next step is to de-solder all wires then re-solder wires to new FC when it arrives in a day or 2. If no go then it’s to order a new Transmitter (Taranis) and kinda hoping not to do that ><
Thanks again!
The very first thing on the page is to check your stick inputs in Betaflight :)
Check if SBUS is setup properly?
Another I’d try is to backup and then reset all the settings, and start from scratch, could just be a configuration issue.