APM2.8 Output Channel 2 not working - NOOB - 1st post

APM2.8 Output Channel 2 not working - NOOB - 1st post

I’ve set up my quad with an APM 2.8 with latest firmware and everything is working… except the output channel 2. I can turn the APM on, stabalise mode, GPS lock, arm the motors and get them spinning except which ever motor is plugged into output 2. I’ve plugged in different motors into that channel to make sure I didn’t have a bad motor or ESC, and they all work when connected to outputs 1,3, or 4.

I do get some power to the Afro ESC 30Amp - green light - then it goes off… all others remain on and armed.

I’ve just changed from a KK2.0 FC as I wanted to add GPS, but this is frying my brain :neutral_face:

I’ve calibrated my ESC’s ‘all in one’ and singularly.

Any idea on what might be going on, or a potential fix I could try?

Please post a dataflash log to help troubleshoot your issue.

Thanks, TCIII, for a quick response …

I have attached what I believe to be the correct logs … I hope it makes more sense to you than me !

I’d love to get this thing in the air !


Here is an Auto Analysis of your dataflash log:
Size (kb) 426.6494140625
No of lines 5906
Duration 0:02:13
Vehicletype ArduCopter
Firmware Version V3.2.1
Firmware Hash 36b405fb
Hardware Type
Free Mem 0
Skipped Lines 0

Test: Autotune = UNKNOWN - No ATUN log data
Test: Balance/Twist = GOOD -
Test: Brownout = GOOD -
Test: Compass = GOOD - No MAG data, unable to test mag_field interference

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = UNKNOWN - No IMU log data
Test: Parameters = GOOD -
Test: PM = GOOD -
Test: Pitch/Roll = GOOD -
Test: Thrust = FAIL - Avg climb rate 5.92 cm/s for throttle avg 983
Test: VCC = GOOD -

You need to increase the amount of data being collected in the dataflash log as you have no IMU or GPS data. Looks like you have a Thrust issue.


Thanks, again, TCIII …

A couple of things …

I am going outside to get a GPS fix and arm … and then running to my PC to plug in to see what MP says on the display.
I agree - I have received a PRE-ARM: BAD VELOCITY error in Mission Planner - is that related to the thrust issue you mention ?
Is the log record immaterial, in this case, as the ESC is not even receiving power ?

I have attached another log and a pic of my quad … dead on the floor !

I hope this helps diagnosis a little bit further. Thanks, again, for your help …

If you haven’t already, check that the output pin itself doesn’t have a loose/broken solder joint (mine did).


By George[K]! I think he’s got it !

The reason why I bought an enclosed APM board was so that I don’t need to get ‘involved’ at the early stages … that will come later :wink:

So, tentatively, I opened her up … and the fault was immediately obvious ! [ I’m just glad it was a physical fix, rather than anything too techy :open_mouth:

TCIII & GeorgeK - Thank you !

Just hope the weather is fine tomorrow … I’m going flying !

Cheers … :smiley: